IE49704B1 - Novel steroid 5alpha-reductase inhibitors - Google Patents

Abstract

The title compounds are of formula wherein R is =O, -OH, -OCO(C1-5 alkyl), -COOH, -CH2OH, -CHO, -COO(C1-6 alkyl), -COCH3, -CH(CH3)-COOH, -CH(CH3)- COO(C1-6 alkyl), beta -O-(CH2)3- alpha or a 20 beta -isomer of -CH(CH3-)- CH2OH, CH(CH3)-CHO, -CH(CH3)-COOH or -CH(CH3)- COO(C1-6 alkyl). These compounds have utility as inhibitors of the enzyme which converts testosterone to dihydrotestosterone, and may be made up into pharmaceutical compositions for treating acne and oily skin.

Description

This invention relates to the use of certain steroid compounds for treatment of acne and oily skin, baldness and of prostate hypertrophy through inhibition of testosterone 5α-reductase.

It is known that skin responds to androgens and is an active site of androgen metabolism. Testosterone is metabolized in the skin to dihydrotestosterone (DHT) which is a more potent androgen than testosterone. As set out in Arch. Dermatol., Ill, 1496 (1975) there is considerable evidence that DHT is involved in the pathogenesis of acne as well as other androgen associated conditions. Studies in the hamster flank organ, which is an androgen dependent sebaceous structure, indicate that DHT stimulates the growth of this structure. It has been found that acne-bearing skin produces from 2 to 20 times more DHT than normal skin. Therefore, it is believed that agents capable of blocking the formation of DHT would be effective in the treatment of acne. Further, many studies indicate that prostatic hypertrophy may be treated by administering an agent which prevents the formation of DHT from testosterone.

Testosterone is converted to DHT by the enzymatic action of testosterone 5a-reductase. One possible means of blocking the formation of DHT Is to inhibit the activity of testosterone 5a-reductase. In the treatment of acne the activity of the 5a-reductase enzyme is preferably inhibited locally, i.e., in the region of the acne-bearing skin.

Many workers in the art have believed that steroid compounds effective for testosterone 5a-reductase inhibition required a Δ1*-3-keto configuration.

The numerous compounds disclosed in O.S. Patent Specification Nos.·3,917,829 and 4,088,760 all contain the ring Α Δ*-3-οηβ structure. It might be inferred that the presence of the other ring A substituents would add little, and might even detract from, the usefullness of such compounds for inhibition purposes.

It may be noted that the Δ*-3 keto steroids previously suggested for inhibition of the 5a-reductase act through competitive inhibition and their effectiveness depends upon maintaining a significant, perhaps substantial, concentration of inhibitor in the target organ, e.g., in the patient's skin or in the prostate. Manifestly competitive inhibitors offer a lesser degree of effectiveness than irreversible or quasi-irreversible inhibitors.

A theory for irreversible inhibition of 5areductase and Δ’-3-keto isomerase has been offered in U.S. Patent Specification No. 4,087,461. Briefly this theory requires a steroid containing a potentially reactive group, which group becomes reactive when the target enzyme carries out Its transformation. At that time a chemical reaction, e.g., an alkylation, takes place directly at the active site of the enzyme or so closely adjacent thereto as to irreversibly inhibit the enzyme. U.S.

Patent Specification No. 4,087,461 suggests allenio secosteroids are irreversible inhibition of Δ5-3-keto steroid isomerases and of testosterone 5a-reductase and describes the enzyme catalyzed transformation as involving reaction at the C-4 position.

The novel compounds of the present invention are 4-substituted steroids which can inhibit the activity of 5a-reductase, rendering said compounds useful in treating acne or oily skin. It is not known whether the 9 7 0 4 inhibition is irreversible or is near-irreversible, i.e., quasi-irreversible, because the 4-substituted steroid does not readily decouple from the enzyme.

The novel compounds have the formula wherein R is =0, —OH, —0C0(C^alkyl) , —COOH, —CHjOH, —CHO, —COO(C1_galkyl) , —COCHj, —CS(C8./—COOH—CHfCHj) —C00(C^_galkyl), 8—0—(CH2)3—a or a 20R-isomer of —CH(CH3)—CH2OH or —CH(CH3)—CHO. β—0—(CH2)3—a means that R forms, with the 17-C atom, a cyclic ether, the 0 atom of which is attached to the 17-C atom in β configuration, having the formula This group is referred to herein as the furan ring which 15 R may represent.

It is believed that the inhibition attributable to the presence of the N2 substituent at C-4 is cumulative of the competitive inhibition attributable to the presence of a preferred 17 substituent. By and large, the 17 sub20 stituents, i.e., R, are those described in the prior art, e.g., U.S. Patent Specification Nos. 3,917,829 and 4,088,760.

R is preferably p-O-(CHj)3-a or, more preferably, 2OR-CH(CH3)-CH2OH, 2OR-CH(CH3)-CHO or 2OR-CH (CH-j)-COOH.

As set forth hereinabove there is evidence that dihydrotestosterone (DHT) which is a metabolite of testosterone has a stimulatory effect on sebaceous glands and thereby is involved in the pathogenesis of acne, and agents which inhibit the formation of DHT would be useful in the treatment of acne. The compounds employed in the present invention have been found to be inhibitors of testosterone 5o*reductase, the enzyme which transforms testosterone to the more active androgen DHT. Hence, the compounds employed in the present invention, that is, the compounds of the formulae set out above, being inhibitors of testosterone 5 The potency of an enzyme inhibitor is often expressed in terms of its inhibition constant, Ki, which is defined mathematically in terms of established relationships of enzyme-catalyzed reaction rates to inhibitor and substrate concentrations. The derivation of these relationsnips and the mathematical definition of Ki are found in standard texts on enzymology. Simply stated, the Ki expresses quantitatively the combining power of the inhibitor for the enzyme; the lower the value of Ki, the greater the combining power (affinity). In the case of the substrate, the corresponding value is known as the Km, the relationship to combining power being roughly the same. The following comparison exhibits the increase in combining power for 5a-reductase obtained in the compounds of this series, over that of the substrate (testosterone) or one of the most potent previously known Inhibitors.

IH Ki 1.0 x 10 ®M (Km) testosterone 2.2 x 10'7M 2.0 x 10*®M It can be seen that the representative compound of the present invention possesses 50 times the affinity of the substrate for the enzyme, and is at least 10 times as q, potent as the previous inhibitor.

The utility of the compounds employed in the present invention can be demonstrated by the ability of the compounds to inhibit the activity of 5a-reductase isolated from rat prostate gland. For example, using prostate lo microsomes containing testosterone 5a-reductase in an amount equivalent to 180 mg of fresh tissue, and 4- l*C-testosterone at a concentration of 2 x 10®M, at 5 x 10’aM (5a,20R)-4-diazo-21-hydroxy-20-methylpregnan5- one was found to inhibit the conversion of testosterone IS to DHT and androstanediol (ADIOL) overall by 4-9^· Under the same conditions, a concentration of 5 x 10’7M inhibited the conversion of testosterone to 5 To achieve the desired anti-acne or anti-seborrheic effect the compounds employed in the present invention can be administered orally, parenterally, for example, intramuscularly and subcutaneously, and topically to a patient in need of treatment. Topical administration is preferred. As used herein in association with the treatment of acne or oily skin the term patient is taken to mean a warm-blooded mammal, for example, primates, human males and females having an acne condition or an oily skin condition in need of treatment. The compounds of the invention can be administered alone or suitably admixed in the form of a pharmaceutical preparation to the patient being treated. The amount of compound administered will vary with the severity of the acne condition or oily skin condition and repetitive treatment may be desired. For oral and parenteral administration the amount of compound administered, that is, the anti-acne or anti-seborrheic effective amount, is from 0.1 to 50 mg/kg of body weight per day and preferably from 1 to JO mg/kg of body weight per day. Unit dosages for oral or parenteral administration may contain, for example, from 5 to 200 mg of the active ingredient. For topical administration the anti-acne or anti-seborrheic effective amount of the compounds of the invention on a percent basis can vary from 48704 0.001% to 5% snd preferably from 0.005% to 1%. For topical administration the formulated active ingredient, that is, a compound of the invention can be applied directly to the site requiring treatment or can be applied to the oral or nasal mucosa. Applicator sticks carrying the formulation may be employed in administering the compounds.

In the treatment of benign prostatic hypertrophy (bph) the compounds of the invention may be administered in various manners to the patient being treated to achieve the desired effect. As used herein in the treatment of bph the term patient is taken to mean male warm blooded animals, such as male rats, male dogs and human males. The compounds can be administered alone or in combination with one another. Also, the compounds can be administered in the form of a pharmaceutical preparation. The compounds may be administered orally, parenterally, for example, intravenously, intraperitoneally, intramuscularly or subcutaneously, including injection of the active ingredient directly into the prostate. The amount of compound administered will vary over a wide range and can be any effective amount. Depending on the patient to be treated, the condition being treated and the mode of administration, the effective amount of compound adminis25 tered will vary from about 0.1 to 50 mg/kg of body weight per day and preferably from 1 to 30 mg/kg of body weight per day. Unit dosages for oral or parenteral administration may contain, for example, from 5 to 200 mg of a compound of the invention.

These dosage ranges represent the amount of compound that will be effective in reducing the size of the prostate, i.e., the amount of compound effective in treating bph. The compounds can be administered from onset of hypertrophy of the prostate to regression of the symptoms, and may be used as a preventive measure.

Topical formulation can be, for example, in the form of a solution, suspension, emulsion, gel or cream of 48704 either the oil-in-water or water-in-oil type, ointment, paste, jelly, paint or powder. Suitable bases for the topical preparation may be of any conventional type such as oleaginous bases, for example, olive oil, cottonseed oil, petrolatum, white petrolatum, mineral oils, silicones, such as, dimethylpolysiloxane, or methylphenylpolysiloxane, lanolines, polyethyleneglycol, glyceryl monosterate, methylcellulose and hydroxymethyl cellulose. The topical formulation may contain pharmaceutically acceptable surfactants, wetting agents, dispersing agents, emulsifiers, penetrants, emollients, detergents, hardeners, preservatives, fillers, anti-oxidants, perfumes, cooling agents, such as, menthol, soothing agents, such as, camphor, or coloring agents, such as, zinc oxide. Aerosol preparations of a solution, suspension or emulsion containing the active ingredient in the form of a finely ground powder can also be employed for topical administration. The aerosol may be packaged In a pressurized aerosol container together with a gaseous or liquified propellant, for example, dichlorodifluoromethane, dichlorodifluoromethane with dichlorodifluoroethane, carbon dioxide, nitrogen, or propane with the usual adjuvant such as cosolvent and wetting agents as may be necessary or desirable. The compounds may also be administered in a non-pressurized form such as in a nebulizer or atomizer.

Following are illustrative topical pharmaceutical formulations which may be employed in practicing the present invention. The active ingredient in each case, and in all subsequent examples of oral and parenteral formulations, may be named(5a,2OR)-4-diazo-21-hydroxy-20-methylpreanan3-one. Carbopol, Silastic and Hydron are Trade Marks.

SOLUTION {5a,2OR)-4-diazo-21-hvdroxy-20-methyl pregnan-3-one Alcohol Isopropyl myristate Polyethylene glycol 400 Purified water qs ad 0.85 g 78.9 ml 5.0 g .02 100 ml 497 0 4 Combine the alcohol, isopropyl myristate and polyethylene glycol too and dissolve the drug substance therein. Add sufficient purified water to give 100 ml.

A GEL (a) (5a>20R)-4-d i azo-21-hyd roxy-20methy1pregnan-3-one 0.85 9 (b) A1 coho 1 78.9 ml (c) Isopropyl myristate 5.0 9 (d) Polyethylene glycol 400 10.0 9 (e) Carbopol 940 (Carboxypolymethy,ene) .75 9 (f) Triethylamine qs (g) Purified water qs ad 85 9 Disperse the Carbopol 9to in the isopropyl myristate. To ml of alcohol add 7 ml of purified water and the polyethylene glycol too and mix. Combine the two phases and mix until well dispersed. Add sufficient triethylamine to give a neutral pH. Dissolve the drug substance in the balance of the alcohol and mix well into the batch. Add and mix sufficient purified water to provide 85 g of fi ni shed product.

APPLICATOR STICK <a) (5a,20R)-4-d i azo-21-hyd roxy-20methy1pregnan-3-one 0.85 9 ( b) Absolute alcohol 75 ml ic) Polyethylene glycol 400 10.0 9 (d) Isopropyl myristate 5.0 9 25 ie) Stearic acid 4.3 9 (f) Sodi urn hydroxi de 0.55 9 ig) Pur i fied water qs ad 85 g Combine the absolute alcohol, polyethylene glycol toO and isopropyl myristate. Add the stearic acid and heat the mixture to about 65°C. Dissolve the sodium hydroxide in a small amount of water, add and mix. Add sufficient water to provide 85 g of finished product. After formation of the applicator stick base the drug substance is suspended therein immediately before depositing and solidifying the formulation. η 43704 AEROSOL FOAM (a) (5a,20R)-4-diazo-21-hydroxy-20- 1.0 g methylpregnan-J-one (b) Propylene glycol 96.0 g (c) Emulsifying Wax NF XIV 5-0 g (d) Dich1orodif1uoromethane:cryfluorane 6.9 g (20:80) Dissolve the drug substance in the propylene glycol. Add the emulsifying wax and heat to approximately 70°C. Stir while cooling to room temperature. Charge a suitable aerosol unit with this concentrate and 6.9 g of dichlorodifluoromethane:cryofluorane (20:80).

TOPICAL CREAM, VANISHING o/w (a) (5o,20R)-4-diazo-21-hydroxy-20- 1 methylpregnan-J-one (b) Stearyi alcohol 15 (c) Sorbitan Monostearate 2 (d) Polyoxyethylene Sorbitan Monostearate 2.J (e) Propylene glycol 5 (f) Methylparaben 0.025% (g) Propylparaben 0.015% (h) Purified Water qs POWDER (a) (5a,20R)-4-diazo-21-hydroxy-20- 1 methy1pregnan-J-one (b) Silicon dioxide, anhydrous 0.5 (c) Cornstarch, lactose, fine powder qs OLEAGINOUS OINTMENT (a) (5a,20R)-L-diazo-21-hydroxy-20- 1 Methylpregnan-J-one (b) White wax 5 (c) White petrolatum qs 100 ABSORPTION OINTMENT BASE (a) (5ft,20R)-4-diazo-21-hydroxy-20- 1 methyIpregnan-J-one (b) Cholesterol 5 (c) Stearyl alcohol 3 (d) White wax 8 (e) White petrolatum qs loo y 7 υ 4 WATER SOLUBLE OINTMENT DOSE (a) (5a,20R)-4-diazo-21-hydroxy-20- 1 methylpregnan-3-one (b) Polyethylene glycol 400 4o (c) Polyethylene glycol 0 qs 100 PASTE (a) (5a,20R)-4-diazo-21-hydroxy-20- 1 methy1pregnan-3-one (b) Starch 35 (c) Zinc oxide 25 (d) White pretrolatum qs 100 AEROSOL FOAM (a) (5o,20R)-4-diazo-21-hydroxy-20- 1 methy lpregnan-3-one (b) Emulsifying wax 3 (c) Stearyl alcohol 2 (d) Di glycol stearate 2 (e) Propylene glycol 92 The compounds in treating acne and an oily skin condition may be used in combination with other antiacne preparations, antiseptics, anti infective agents, keratolytic agents, for example, resorcinol, comedolytic agents, or agents having a retinoic acidlike action, corticoids or other antiinflammatory agents, thioglycolates, ethyl lactate or benzoyl peroxide. The following formulations are illustrative of pharmaceutical preparations for topical application comprising a compound in combination with a keratolytic agent.

AEROSOL FOAM (a) (5a,20R)-4-diazo-21-hydroxy-20- 1 methy1pregnan-3-one (b) Resorcinol monoacetate 1 (c) Emulsifying wax NF 5 (d) Stearyl alcohol 2 (e) Diglycol stearate ' 2 (f) Propylene glycol gj Dissolve the drug substance in the propylene glycol. Add the emulsifying wax and heat to about 70°C. Stir while cooling to room temperature. Charge a suitable aerosol unit with the concentrate and 6.9 g of dichlorodifluoromethanexcryfiuorane (20:80).

A GEL (a) (5a,20R)-4-diazo-21-hydroxy-20methylpregnan-5-one 0.85 g (b) Resorcinol 0.85 g (c) Alcohol 78.9 ml (d) Isopropyl myristate 5.0 g (e) Polyethylene glycol 400 10.0 9 (f) Carbopoi 940 (earboxypolymethylene) 0.75 g (g) Triethylamine qs (g) Purified water qs ad 85 g Disperse the Carbopol 940 in the isopropyl myristate. To 58 mi of alcohol add 7 ml of purified water and the polyethylene glycol 400 and mix. Combine the two phases and mix until well dispersed. Add sufficient triethylamine to give a neutral pH. Dissolve the drug substance and the resorcinol in the balance of the alcohol and mix well into the batch. Add and mix sufficient purified water to provide 85 9 of finished product.

For oral administration the compounds can be formulated into solid or liquid preparations, such as, capsules, pills, tablets, troches, powders, solutions, suspensions or emulsions. The compounds can be applied in the form of an aerosol containing finely divided particles of the active ingredient or a solution, suspension, or emulsion of the active ingredient. The solid unit dosage forms can be a capsule which can be of the ordinary gelatin type containing the active compound and a carrier, for example, lubricants and inert filler such as lactose, sucrose, and corn starch. In another embodiment, an active compound of the invention can be tableted with conventional tablet bases such as lactose, sucrose and corn starch in combination with binders such as acacia, corn starch or gelatin, disintegrating agents such as potato starch or alginic acids and a lubricant such as stearic acid or magnesium stearate.

For parenteral administration the compounds may be 5 administered as injectable dosages of a solution or suspension of the compound in a physiologically acceptable diluent with a pharmaceutical carrier which can be a sterile liquid such as water-in-oil with or without the addition of a surfactant and other pharmaceutically accept10 able adjuvants. Illustrative of oils which can be employed in these preparations are those of petroleum, animal, vegetable or synthetic origin, for example, peanut oil, soybean oil and mineral oil. In general, water, saline, aqueous dextrose and related sugar solutions, ethanols and glycols, such as, propylene glyco, or polyethylene glycol are preferred liquid carriers, particularly for injectable solutions.

The compounds can be administered in the form of a depot injection or implant preparation which can be formu20 lated in such a manner as to permit a sustained release of the active ingredient. The active ingredient can be compressed into pellets or small cylinders and implanted subcutaneously or intramuscularly as depot injections or implants. Implants may employ inert materials such as biodegradable polymers and synthetic silicones, for example, Silastic, silicone rubber manufactured by the Dow-Corning Corporation.

The following are illustrative pharmaceutical formulations suitable for oral or parenteral administration which may be employed in practicing the present invention: (a) (5o,20R) - A-diazo-21-hydroxy-20methy1pregnan-3-one (b) Lactose (c) Corn starch TABLET g 1.216 Kg 0.3 Kg 48704 Mix the active ingredient, the lactose and corn starch uniformly. Granulate with 10% starch paste . Dry to a moisture content of about 2.5%· Screen through a No. 12 mesh screen. Add and mix the following: (a) Magnesium Stearate 0.015 Kg (b) Corn starch qs ad 1.725 Kg Compress on a suitable tablet machine to a weight of 0.115 g/tablet. SOFT GELATIN CAPSULE (a) (5c,20R)-4-diazo-21-hydroxy-20- 0.25 Kg methylpregnan-3-one (b) Polysorbate 80 0.25 Kg (c) Corn ol1 qs ad 25-0 Kg Mix and fill into 50,000 soft gelatin capsules. IM DEPOT INJECTION Each 1 ml contains the following: (a) (5a,20R)-4-d iazo-21-hydroxy-20- 5.0 mg methylpregnan-3-one (b) Anhydrous chlorobutanol 5.0 mg (c) Aluminum monostearate 50.0 mg (d) Peanut oi1 qs ad 1.0 ml Dissolve or disperse the ingredients in the peanut oi 1. DEPOT-IMPLANT (a) (5o,20R)-4-diazo-21-hydroxy-20- 5 mg methy1pregnan-3-one (b) Dimethylsiloxane 240 mg (c) Catalyst qs Disperse the drug substance in the fluid dimethylsiloxane. Add the catalyst and cast into a suitable monolytic structure .

Alternatively, the drug substance may be enclosed by a precast, polydimethylsiloxane envelope.

Alternatively, the drug substance may be dispersed in a suitable amount of hydroxyethyl acrylate subsequently polymerized and cross-linked by the addition of ethylenedimethacrylate, and an oxidizing agent, to yield a 3dimensional ethylene glycomethacrylate moldable gel (Hydron). 9 7 0 4 IM INJECTIONS A. Oil type: (a) (5o,20R)-4-diazo-21-hydroxy-20methylpregnan-3-one 25 mg (b) BHA, BHT aa 0.01$ w/v (c) Peanut oil or sesame oil qs B. Suspension type: 1.0 ml (a) (5a,20R)-4-di azo-21-hydroxy-20methy1pregnan-3-one 25 mg (b) Sodium carboxymethylcellulose 0.5$ w/v (c) Sodi urn bisulfite 0 .02$ w/v (d) Water for injection, qs BUCCAL OR SUBLINGUAL TABLET 1.0 ml (a) (5a,20R)-4-diazo-21-hydroxy-20methylpregnan-3-one 1$ (b) Calcium stearate 1$ (c) Calcium saccharin 0.02$ (d) Granular manni tol qs M i x and compress on a suitable tablet machine to a wei ght of C ).115 g/tablet.

The compounds herein described can be prepared from the A4-3 keto precursor R I wherein R is as already described, but may be blocked, e.g., forming a siloxy ether or a ketal as appropriate and desirable during the reaction sequence. For instance the reaction sequence set out below, and followed in Example 1 employs a di-methyl tertiary butyl siloxy ether blocking group on the 17-substituent to protect the 17-substituent during the reaction sequence used to add a 4-benzoyl group. Then R may be unblocked and transformed to the ultimate substituent, e.g., oxidized to aldehyde or to an acid oxidation level then esterified, etc., before the diazo transfer reaction is carried out.

When R contains an alcohol, the starting material will be the alcohol itself. If R contains an aldehyde, acid or ester the corresponding alcohol is utilized as the starting material, and later the alcohol group is transformed into the aldehyde, etc.

The alcohol function is protected through forming the dimethyl-t-butyl silyl ether by the technique described by E. J. Corey et ai., J. Am. Chem. Soc. £4, 6190 (1972).

When R«COCHS (i.e., the starting material is progesterone) the side chain is protected by first forming the ketal CH3 0' The (protected) 3-keto A4 steroid, e.g., Compound A of the reaction sequence flow sheet which follows, is subjected to dissolving metal reduction using Li in NH3 in aniline or tert-butvl alcohol for the proton donor at -78° to -35°C for 1 to 60 minutes as generally described by G. Stork et al., J. Am. Chem. Soc. 96, 7H·1·· (197^) · Then the enolate ion is trapped with trimethylsilyl chloride and the resulting enol ether, e.g., Compound B, i soiated. 9 7 0 4 I OS Ϊ4A ι +SiO ι H OS i+ OH C ϋ χ Ή CgHs D η CeHs ? OH ι E CeHs Ns R G θ fl Ns The enolate anion is then regenerated from the enol ether using an alkyllithium, e.g., methyllithium or butyllithium in an ether, such as, tetrahydrofuran or diethyl ether at 0° - 25°C for 1 to 60 minutes, and is then reacted with benzoyl acid chloride or a C2_5 alkanoyl chloride for 1-20 minutes at -100° to -70°Cin, e.g., diethyl ether or tetrahydrofuran (Compound C).

The alcohol function is then unblocked with Θ F or acid as described by E. J. Corey et al., J. Am. Chem. Soc. 94, 6190 (1972) or else by reaction with a tetrafluoroborate salt such as the lithium, sodium, zinc, tin, magnesium, silver, potassium, triphenylcarbenium, trialkyloxonium (the alkyl group is, for example, methyl, ethyl, propyl, or butyl) tetrafluoroborate in an aprotic solvent such as acetonitrile, dimethylformamide or dimethylacetamide, an ether, methylene chloride, chloroform or a combination thereof at frcm 0° to 100°C for 1 to 72 hours. The procedure effects cleavage of the tert-butyldimethylsilyl ether to the corresponding alcohol, both primary and secondary (Compound D).

When R=0H, CH20H or CH(CH3)-CH2OH, the diazo transfer reaction (to compound E) may follow directly, by treatment of equivalent amounts of Compound D and sodium hydride or a trialkylamine, such as, triethylamine, to generate the enolate; £-toluenesulfonyl azide is then added to introduce the diazo function as described by J. B. Hendrickson et al., J. Org. Chem. 33, 3610 (1968). This reaction is usually performed in ether or tetrahydrofuran at 0° to 25°C for 1 to 24 hours.

When R is other than a furan ring or one of the alcohol-containing groups, conversion at the 17-position to the desired 17-substituent is carried out immediately prior to the diazo transfer reaction (as in Compound D to F then to Compound G). 9 7 0 4 The alcohol group may be ozidized to the aldehyde or ketone by standard procedures, for example, using pyridinium chlorochromate as described by E. J. Corey et al., Tet. Letts., 2647 (1975), or using chromium trioxide/pyridine (R. W. Ratcliffe, Org. Syn., 1973) or to the acid using Jones Reagent (R. Bowden et al., J.

Chem. Soc., 39 (1966). The acid may be converted to alkyl esters, using diazomethane for the methyl ester, and the alcohol saturated with HCl gas for higher ethyl esters, or via the acid chloride and the alcohol.

When R is OCOalkyl such compounds are obtained from the alcohol by reaction with a C2~Cg alkanoyl chloride or anhydride in pyridine as solvent (0° to 25°C, 1 to 24 hours).

The diazo transfer reaction can then be conducted on the aldehydes, ketones, acids (using 2 equivalents of NaH), and esters.

When R is -COCH3 the actual starting material for the reaction sequence is the 20-ketal, the ketal protecting group being removed prior to the diazo transfer reaction by exchange in acetone or propanone using £-toluenesulfonic acid as catalyst at 25“ to 6o°C for 1 to 24 hours.

When R is a furan ring, the starting material may be utilised directly without any need for blocking groups and the reacticn sequence proceeds directly fiom the starting conpound to the ultimate diazo compound.

The following examples describe preparation of the 4- diazo compounds of this invention.

EXAMPLE 1 Testosterone dimethyl t-butylsilyiether (Compound A) A mixture of testosterone (1.0 g, 5·5 mmole), _tbutyldlmethylsilyl chloride (627 mg, 4.2 mmole) and imidazole (287 mg, 4.2 mmole) in dimethylformamide (4 ml) is stirred overnight at 40°C. The mixture is then poured into ice water and the resulting precipitate filtered off and recrystallized from methanol to afford 1.55 g.

- Trimethylsiloxy-17 e~(dimethyl-t-butylsiloxy)-5 aandrost-3-ene (Compound B) Testosterone dimethyl-^-butylsilyl ether (12.C g, 29.8 mmole) in tetrahydrofuran (70 mi) is added to ammonia containing aniline (2.7 g, 29.6 mmole) and lithium (625 mg, 89 mmole). After 1 hour the blue solution is treated dropwise with isoprene until the blue color is dissipated. The ammonia is allowed to 9 7 0 4 evaporate and the residue dried under vacuum (0.5 mm). Tetrahydrofuran (50 ml) is then added, the solution cooled to 0°C, and treated with a solution of trimethylsi lyl chloride (12 ml) and triethylamine (12 ml) which had previously been centrifuged. After 15 minutes the mixture is diluted with pentane and washed with chilled 0.5 m HCl, then chilled aqueous sodium bicarbonate, then dried (MgSO4) and concentrated. The residue is crystallized from ethyl acetate to afford 6.6 g. (The mother liquors are chromatographed on silica gel. Elution with 10% ether-pentane affords a fraction which is recrystallized from ethyl acetate (2.2 g). M.P. 126°C. 4-Benzoyl-17B-(dimethyl-t-butylsllyloxy)-5a-androstan-3-one (Compound C) To the enol ether (4.89 g, 10.27 mmole) in ether (20 ml) is added methyl lithium (5-5 ml of a 2.05 M solution, 11.3 mmole). After 1 hour at 25°C the solution is taken up in a syringe and added slowly to a solution of benzoyl chloride (1.45 g, 10.3 mmole) in ether (30 ml) at -70°C. After 5 minutes aqueous ammonium chloride is added and the products isolated by ether extraction. The residue, after evaporation of the ether, is recrystallized from carbon tetrachloride to afford 2.0 g. 4-Benzoyl-1-7B-hydroxy-5a-androstan-3-one (Compound D) The silyl ether (1.64 g, 3*2 mmole) in dichloro25 methane (50 ml) is treated with tritylfluoroborate (1.27 9 3.84 mmole) for 1 hour at 25°C. This solution is then washed with aqueous ammonium chloride, dried and evaporated. The residue is chromatographed on silica gel. Elution with 1% methanol-chloroform afforded a fraction which is recrystallized from ethyl acetate-pentane (1.0 g). 4-D i azo-17B-hydroxy-5a-androstan-3-one (Compound E): The diketone (3-5 mg, 0.8 mmole) in tetrahydrofuran (2.0 ml) is added to sodium hydride (48 mg, of a 50% dispersion) in tetrahydrofuran (5 ml). After 30 minutes, tosylazide (157 mg, 0.8 mmole) in tetrahydrofuran is added and the mixture stirred overnight at 25°C, Ether is then added, the mixture filtered, then washed with water, dried and evaporated. The residue is chromatographed, the fraction eluted with 70% ether-petrol being collected. Recrystallization from chloroform-hexane afforded yellow crystals (26 mg), m.p. 171°.

EXAMPLE 2 4-Benzoyl-5c-androstane-3,17-dlope 4-Benzoyl-17g-hydroxy-r5a-androstan-3-one made as. in Example 1 (788 mg, 2 mmole) in 2 ml of CH8C18 is added to pyridinium chlorochromate (650 mg, 3 mmole) suspended in CHaCla (2 ml) at 25°C. After 2 hours, ether is added and the solvent decanted. This is then filtered through florisil, the eluate evaporated and the residue recrystallized from chloroform-heptane. 4-D i azo-6-g-androstane>t3 ,17-dione The triketone (350 mg, 0.8 mmole) in tetrahydrofuran (2.0 ml) is added to sodium hydride (48 mg, of a 50% dispersion) in tetrahydrofuran (5 ml). After 30 minutes, tosylazide (157 >”9, 0.8 mmole) in tetrahydrofuran is added and the mixture stirred overnight at 25°C. Ether is then added, the mixture filtered, then washed with water, dried and evaporated. The residue is chromatographed, the fraction eluted with 70% ether-petrol being collected. Recrystallization from chloroform-hexane afforded yellow crystals (35 nig).

EXAMPLE 3 The reaction sequence employed in this example is illustrated in the following formula sequence: 8 7 0 4 48704 (20R)-2l-Hydroxy-20-methylpregn-4-en-3-one To the aldehyde starting material (16.4 g, 50 mmole) in ethanol (250 ml) and THF (50 ml) at 0°C is added a solution of NaBH^ (675 mg, 12.5 mmole) in ethanol (125 ml) dropwise. The mixture is stirred at 25°C overnight, then neutralized by the addition of glacial acetic acid, then concentrated on the rotary evaporator. The residue is taken up in chloroform and washed with saturated agueous NaHCOg, then brine, then dried and concentrated. The residue is recrystallized from chloroform-pentane to afford a colorless solid (12.6 g, 77%). M.P. 132.5°C. (20R)-21-(Dimethyl-t-butylsiloxy)-2O-methylpregn-4-en-3one A mixture of (20R)-21-hydroxy-20-methylpregn-4-en3-one, t-butyldimethylsilyl chloride (10 g, 30.3 mmole) and imidazole in dimethylformamide (50 ml) is stirred overnight at 40°C. The mixture is then poured into ice water and the resulting precipitate filtered off and recrystallized from methanol to afford 8.6 g. (5a,20R)-3-Trimethylsiloxy-21-(dimethyl-t-butylsiloxy)-20methylpregn-3-ene__ (20R)-21-(Dimethyl-t-butylsilyloxy)-20-methylpregn4-en-3-one (2.0 g, 4.5 mmole) in tetrahydrofuran (20 ml) is added to ammonia containing aniline (420 mg, 4.5 mmole) and lithium (100 mg, 15 mmole). After 1 hour the blue solution is treated dropwise with isoprene until the blue color is dissipated. The ammonia is allowed to evaporate and the residue dried under vacuum (0.5 mm). Tetrahydrofuran (20 ml) is then added, the solution cooled to o°C, and treated with a solution of trimethylsilyl chloride (4 ml) and triethylamine (4 ml) which had previously been centrifuged. After 15 minutes the mixture is diluted with pentane and washed with chilled 0.5 M HCI, then chilled agueous sodium bicarbonate, then dried (MgS04) and con497 0 4 centrated. The residue is crystallized from ethyl acetate to afford 1.6 g, M.P. 113 °C. (5a,2OR)-4-Benzoyl-21-(dimethyl-t-butylsiloxy)-20methy1-pregnan-3-one To the enol ether (5a,2OR)-3-trimethylsiloxy21-(dimethyl-t-butylsiloxy)-20-methylpregn-3-ene (5.08 g, 9.8 mmole) in ether (20 ml) is added methyl lithium (5.5 ml of a 2.05 M solution, 11.3 mmole). After 1 hour at 25°C the solution is taken up in a syringe and added slowly to a solution of benzoyl chloride (1.54 g, 1.27 mmole) in ether (30 ml) at -70°C. After 5 minutes aqueous ammonium chloride is added and the products isolated by ether extraction. The residue, after evaporation of the ether, is recrystallized from chloroform-heptane to afford 450 mg, M.P. 169°C. (5g,20R)-4-Benzoyl-21-hydroxy-20-methylpregnan-3-one The silyl ether (5a,2OR)-4-benzoyl-21-(dimethylt-butylsilyloxy)-20-methylpregnan-3-one (1.06 g, 2.0 mmole) in dichloromethane (50 ml) is treated with trityl20 fluoroborate (660 mg, 2 mmole) for 1 hour at 25°C. This solution is then washed with aqueous ammonium chloride, dried and evaporated. The residue is chromatographed on silica gel. Elution with 1% methanol-chloroform affords a fraction which is recrystallized from ethyl acetate-pen25 tane (500 mg). M.P. 236-238°C. 48704 (5α,2OR)-4-Diazo-21-hydroxy-20-methylpregnan-3-one The (5α,2OR,-4-benzoyl-21-hydroxy-2 O-methylpregnan-3-one (436 mg, 1.0 mmole) in tetrahydrofuran (2.0 ml) is added to sodium hydride (48 mg, of a 50% dispersion) in tetrahydrofuran (5 ml). After 30 minutes, tosylazide (196 mg, 1.0 mmole) in tetrahydrofuran is added and the mixture stirred overnight at 25°C. Ether is then added, the mixture filtered, then washed with water, dried and evaporated. The residue is chromatographed on silica gel, the fraction eluted with 70% ether-petrol being collected. Recrystallization from chloroform-hexane affords yellow crystals (30 mg), M.P. (210° decomp.), of (5a,2OR)-4-diazo-21-hydroxy-20-methylpregnan-3-one.

Using (5a,2OR)-4-benzoyl-3-oxopregnane-20oarboxaldehyde; (5a,20R)-4-benzoyl-3-oxopregnane-20carboxylie acid esters; 4-benzoyl-5a-androstane-3,17dione; or 4-benzoyl-5a-pregnane-3,20-dione, the corresponding 4-diazo-steroid may be prepared by the diazo transfer reaction as in Example 2.

EXAMPLE 4 (5a,2OR)-4-Benzoyl-3-oxopregnane-20-carboxaldehyde (5 a^2OR)-4-Benzoyl-21-hydroxy-20-methyl pregnan-3-one of Example 3 (872 mg, 2 mmole) in dichloromethane (2 ml) is added to pyridinium chlorochromate (650 mg, 3 mmole) suspended in dichloromethane (2 ml) at 25°C. After 2 hours ether (20 ml) is added and the solvent decanted.

This is then filtered through Florisil, the eluate evaporated and the residue recrystallized from chloroform10 heptane. (5g,2OR)-4-Dlazo-3-oxopregnane-20-carboxaldehyde The diketone (350 mg, 0.8 nmole) in tetrahydrofuran (,2.0 ml) is added to sodium hydride (48 mg, of a 50% dispersion) in tetrahydrofuran (5 ml). After 30 minutes, tosylazide (157 mg, 0.8 mmole) in tetrahydrofuran is added and the mixture stirred overnight at 25°C. Ether is then added, the mixture filtered, then washed with water, dried and evaporated. The residue is chromatographed, the fraction eluted with 70% ether-petrol being collected. Recrystallization from chloroform-hexane affords yellow crystals (15 mg).

EXAMPLE 5 (5a,2OR)-4-Benzoyl-3-oxopregnane-20-carboxylic acid The alcohol of Example 3 (872 mg, 2 mmole) in acetone ^5 ml) is treated with excess Jones reagent at 25°C for hours. Saturated sodium chlorid is then added and the mixture extracted with chloroform. The organic phase is washed well with aqueous sodium chloride, then dried and evaporated. The residue is recrystallized from methanol .

Treatment with ethereal diazomethane in excess overnight, followed by evaporation of the solvent leads to the methyl ester.

Treatment of 300 mg of acid with a saturated solu35 tion of isobutylene in methylene chloride (50 ml) overnight at 25°C containing H2SO4 (2 drops) as catalyst affords the .t-butyl ester. Conduct of the diazo transfer reaction on the 208-carboxylate is below exemplified by transformation of the .t-butyl ester. jfcrButyl(5a,2OR)-4-dlazo-3-oxopregnane-20-carboxylate The .t-butyl ester diketone (400 mg, 0.8 mmole) in tetrahydrofuran (2.0 ml) is added to sodium hydride (48 mg, of a 50% dispersion) in tetrahydrofuran (5 ml). After 30 minutes, tosylazide (157 mg, 0.8 mmole) in tetrahydrofuran is added and the mixture stirred overnight at 25°C· Ether is then added, the mixture filtered, then washed with water, dried and evaporated. The residue is chromatographed, the reaction eluted with 70% ether-petrol being collected. Recrystallization from chloroformhexane affords yellow crystals (40 mg).

EXAMPLE 6 The reaction sequence employed in this example is illustrated in the following formula sequence. 9 7 0 4 • 49704 17g— (D ί methyl -_t-butyls i 1 yloxymethy)) androst-4-en-5-one A mixture of 176 - hydroxymethylandrost-4-en-5-one (1.0 g, 5.5 mmole), .t-butyldimethyisi lyl chloride (627 mg, 4.2 mmole) and imidazole (287 mg, 4.2 mmole) in dimethylformamide (4 ml) is stirred overnight at 40°C. The mixture is then poured into ice water and the resulting precipitate filtered off and recrystallized from methanol to afford 1-55 g· -Trimethylsi loxy-176-(dimethyl-t-butylsiloxymethyl)5a-andr0st-3-ene 176-(Dimethy 1 -Jt-butyl si ly loxymethyl) androst-4-en-5-one (12.0 g, 29-8 mmole) in tetrahydrofuran (70 ml) is added to ammonia containing aniline (2.7 9, 29*8 mmole! in lithium (625 m , 89 mmole). After 1 hour the blue solution is treated dropwise with isoprene until the blue color dissipates. The ammonia is allowed to evaporate and the residue dried under vacuum (0.5 mm). Tetrahydrofuran (50 ml) is then added, the solution cooled to 0°C, and treated with a solution of trimethylsilyl chloride (12 ml) and triethylamine (12 ml) which had previously been centrifuged. After 15 minutes the mixture is diluted with pentane and washed with chilled 0.5 m HCI, then chilled aqueous sodium bicarbonate, then dried (MgSO4) and concentrated. The residue is crystallized from ethyl acetate to afford 6.6 g. The mother liquors are chromatographed on silica gel. Elution with 10# ether-pentane affords a fraction which is recrystallized from ethy] acetate (2.4 g). 4-Benzoy 1 -176-(dimethvl-fc-butylsilyloxymethvl-5aandrostan-3-one To the enol ether (4.89 9» 10.27 mmole) in ether (20 ml) is added methyl lithium (5·5 ml of a 2.05 M solution, 11.5 mmole). After 1 hour at 25°C the solution is taken up in a syringe and added slowly to a solution of benzoyl chloride (1.45 g, 10.5 mmole) in ether (50 ml) at 70°C. After 5 minutes aqueous ammonium chloride is added and the products isolated by ether extraction. 9 7 0 4 The residue, after evaporation of the ether, is recrystal iized from carbon tetrachloride to afford 2.2 g. 4-Benzoyl-17B-hydroxymethyl-5n-androstan-3-one The silyl ether (1.64 g, 3.2 mmole) in dichloromethane 5 (50 ml) is treated with trity1f1uoroborate (1.27 9, 3-84 mmole) for 1 hour at 25°C. This solution is then washed with aqueous ammonium chloride, dried and evaporated.

The residue is chromatographed on silica gel. Elution with 1$ methanol-chloroform affords a fraction which is recrystallized from ethylacetate-pentane (800 mg). 4-D i azo-17B-hydroxymethyl-5g-androstan-3-one The diketone (350 mg, 0.8 mmole) in tetrahydrofuran (2.0 ml) is added to sodium hydride (48 mg, of a 50$ dispersion) in tetrahydrofuran (5 ml). After 30 minutes, tosylazide (157 m9, 0.8 mmo.le) in tetrahydrofuran is added and the mixture stirred overnight at 25°C. Ether is then added, the mixture filtered, then washed with water, dried and evaporated. The residue is chromatographed, the reaction eluted with 70$ ether-petrol being collected. 2C Recrystallization from chloroform-hexane affords yellow crystals (30 mg).

EXAMPLE 7 The 4-benzoyl-»17g-hydroxymethyl-5c(-andro stan-3-one can be oxidized to the corresponding 178 aldehyde or 178 acid steroids, then converted to the 4diazo derivative.

(A ) Methyl 4-benzoy1-3-oxo-5g-androstane-17B-carboxylate The alcohol (872 mg, 2 mmole) in acetone (5 ml) is treated with excess Jones reagent at 25°C for 4 hours.

Saturated sodium chloride is then added and the mixture extracted with chloroform. The organic phase is washed well with aqueous sodium chloride, then dried and evaporated. For recovery of the 178 carboxylic acid the residue is recrystallized from methanol. For produc35 tion of 17a.-carboxy late esters, e.g., the methyl ester, the residue is treated with an excess of etheral diazo33 methane. After 10 minutes the solvents are evaporated and the residue recrystallized from methanol.

Methyl 4-diazo-3-oxo-5g-androstane-17B-carboxvlate The di ketone (350 mg, 0.8 mmole) in tetrahydrofuran 5 (2.0 ml) is added to sodium hydride (48 mg, of a 50# dispersion) in tetrahydrofuran (5 ml). After 30 minutes, tosylazide (157 mg, 0.8 mmole) in tetrahydrofuran is added and the mixture stirred overnight at 25°C. Ether is then added, the mixture filtered, then washed with water, dried and evaporated. The residue is chromatographed, the fraction eluted with 70# ether-petrol being collected. Recrystallization from chloroform-hexane affords yellow crystals (30 mg). 4-D iazo-3-oxo-5a-androstane-17B.-carboxvllc acid 15 The 17S-carboxylic acid (350 mg, 0.8 mmole) in tetrahydrofuran (2.0 ml) is added to sodium hydride (96 mg, 2 mmole of a 50# dispersion) in tetrahydrofuran (5 ml). After 30 minutes, tosylazide (157 mg, 0.8 mmole) in tetrahydrofuran is added and the mixture stirred over20 night at 25°C. Acetic acid (60 mg) is then added followed by ether, the mixture filtered, then washed with water, dried and evaporated. The residue is chromatographed, the reaction eluted with 70# ether-petroi being collected. Recrystallization from chloroform-hexane affords yellow crystals (20 mg).

(B) 4-Benzov1 -3-oxo-5 a-androstane-17g-carbpxaldehyde The alcohol (872 mg, 2 mmole) in dichloromethane (2 ml) is added to pyridinium chlorochromate (6p mg, 3 mmole) suspended in dichloromethane (2 ml) at 25°C.

After 2 hours ether (20 ml) is added and the solvent decanted. This is then filtered through florisil, the eluate evaporated and the residue recrystallized from ch1oroform-heptane.

A.p iazo-3-ox0-5a-androsbane-17 g;-carboxaldehyde The diketone (350 mg, 0.8 mmole) in tetrahydrofuran (2.0 ml) is added to sodium hydride (48 mg, of a 50# 9 7 0 4 dispersion) in tetrahydrofuran (5 ml). After 30 minutes, tosylazide (157 mg, 0.8 mmole) in tetrahydrofuran is added and the mixture stirred overnight at 25°C. Ether is then added, the mixture filtered, then washed with water, dried and evaporated. The residue is chromatographed, the reaction eluted with 70% ether-petrol being collected. Recrystallization from chloroform-hexane affords yellow crystals (26 mg).

EXAMPLE 8 One g of 4-benzoy1-17P-hydroxy-5a-androstan-3-one· one prepared as in Example 1 in pyridine (5 ml) and acetic anhydride (5 ml) is maintained at 25°C for 10 hours, then diluted with ether. The ether solution is washed with 1 N HCl, saturated NaHCOs, then dried, evapo15 rated and the residue crystallized from ethyl acetate to afford the 17-acetate. 4-D iazo-iyB^acetoxv-Sg-androstan-S-one The triketone (350 mg, 0.8 mmole) in tetrahydrofuran (2.0 ml) is added to sodium hydride (48 mg, of a 50% dispersion) in tetrahydrofuran (5 ml). After 30 minutes, tosylazide (157 mg, 0.8 mmole) in tetrahydrofuran is added and the mixture stirred overnight at 25°C. Ether is then added, the mixture filtered, then washed with water, dried and evaporated. The residue is chromato25 graphed, the fraction eluted with 70% ether-petrol being collected. Recrystallization from chloroform-hexane affords yellow crystals (30 mg).

EXAMPLE 9 Conversion of progesterone is illustrated in this examp 1e. 3-Trimethyl siloxy-_20-ethylenedioxy-5a-pregn-3-ene Progesterone 20-ethylenedioxy ketai (10.7 g, 30 mmole) in tetrahydrofuran (70 ml) is added to ammonia containing aniline (2-7 9, 30 mmole) and lithium (625 m9, 89 mmole).

After 1 hour the blue solution is treated dropwise with isoprene until the blue color dissipates. The ammonia 437 0 4 is allowed to evaporate and the residue dried under vacuum (0.5 mm). Tetrahydrofuran (50 ml) is then added, the solution cooled to 0°C, and treated with a solution of trimethylsilyl chloride (12 ml) and triethylamine (12 ml) which had previously been centrifuged. After 15 minutes the mixture is diluted with pentane and washed with chilled 0.5 M HCl, then chilled aqueous sodium bicarbonate, then dried (MgSO4) and concentrated. The residue is crystallized from ethyl acetate to afford 6.0 g. 4-Benzovl -20-ethylenedioxy-5a-pregnaii-3-one To the enol ether (4.4 g, 10.2? mmole) in ether (20 ml) is added methyl lithium (5-5 ml of a 2.05 M solution, 11.3 mmole). After 1 hour at 25°C the solution is taken up in a syringe and added slowly to a solution of benzoyl chloride (1.45 g, 10.3 mmole) in ether (30 ml) at -70°C. After 5 minutes aqueous ammonium chloride is added and the products isolated by ether extraction. The residue, after evaporation of the ether, is recrystallized from carbon tetrachloride to afford 2.1 g.

The acetal (1.1 g) in acetone (100 ml) containing £-toluenesulfonic acid (100 mg) is stirred overnight at 25°C, then the solvent evaporated. The residue is dissolved in ether and washed with aqueous NaHCOa, then dried and evaporated to afford the triketone (800 mg). 4-D iazo-5a-PEeqnan-3,20-dlone The triketone (355 nig, 0.8 mmole) in tetrahydrofuran (2.0 mi) is added to sodium hydride (48 mg, of a 50% dispersion) in tetrahydrofuran (5 ml). After 30 minutes, tosylazide (157 mg, 0.8 mmole) in tetrahydrofuran is added and the mixture stirred overnight at 25°C. Ether is then added, the mixture filtered, then washed with water, dried and evaporated. The residue is chromatographed, the fraction eluted with 70% ether-petrol being collected. Recrystai1ization from chloroform-hexane affords yellow crystals (40 mg).

EXAMPLE 10 Conversion of 4',5' dihydrospiro [androst-4-ene-17,2 (3'H) furan]-3-one is illustrated in the following formula sequence: CeH g 4',5'-Dihydrospi γοΓ5-trimethy 1 siloxy-Sa-androst5-ene-17,2'(5'H) furan) Cyclic ether (9.8 g, 30 mmole) in tetrahydrofuran (70 ml ) is added to ammonia containing aniline (2-7 g, mmole) and lithium (625 mg, 89 mmole). After 1 hour the blue solution is treated dropwise with isoprene until the blue color dissipates. The ammonia is allowed to evaporate and the residue dried under vacuum (0.5 mm). Tetrahydrofuran (50 ml) is then added, the solution cooled to 0°C, and treated with a solution of trimethylsilyl chloride (12 ml) and triethylamine (12 ml) which had previously been centrifuged. After 15 minutes the mixture is diluted with pentane and washed with chilled aqueous sodium bicarbonate, then dried (MgSO4) and concentrated. The residue is crystallized from ethyl acetate to afford 7-0 g. • 49704 4', 5 ' -D i hyd rosp! rof^-benzoy 1 -5a-androstane-17.2' (3'-H)furanl-3-one To the enol ether (4.5 g, 10.27 mmole) in ether (20 ml) is added methyl lithium (5-5 ml of a 2.05 M solution, 11.3 mmole). After 1 hour at 25°C the solution is taken up in a syringe and added slowly to a solution of benzoyl chloride (1.45 g, 10.5 mmole) in ether (50 ml) at -70°C. After 5 minutes aqueous ammonium chloride is added and the products isolated by ether extraction.

The residue, after evaporation of the ether, is recrystallized from carbon tetrachloride to afford 2.2 g. 4' ,5'-D ihydror4-diazo-5g-androstane-17' ,2' (3'-H) furanl-5-one The diketone (320 mg, 0.8 mmole) in tetrahydrofuran (2.0 ml) is added to sodium hydride (48 mg, of a 50$ dispersion) in tetrahydrofuran (5 ml). After 30 minutes, tosylazide (157 mg, 0.8 mmole) in tetrahydrofuran is added and the mixture stirred overnight at 25°C. Ether is then added, the mixture filtered, then washed with water, dried and evaporated. The residue is chromatographed, the fraction eluted with 70$ ether-petrol being collected. Recrystallization from chloroform-hexane affords yellow crystals (35 mg).

Alternatively, the protection-deprotection sequence may be achieved by beginning with an aldehyde, for example, as illustrated in the following sequence by compound H protected as an acetal by treatment of 1 equivalent of aldehyde with 1 equivalent of ethyleneglycol using £-toluenesuifonic acid as a catalyst in benzene or toluene solution at a temperature of about 80° to 120°C and removing excess water, for example, by using a Dean Stark trap. The aldehyde, protected as the acetal, is then subjected to dissolving metal reduction using lithium in ammonia in aniline or tert-butanol for the proton at -78° to 33°C for 1 to 60 minutes. The enolate ion is trapped with trimethylsilyl chloride as described above. The enolate anion is regenerated using alkyl lithiums, e.g., methyl or butyl lithium in ethers, such as, tetrahydrofuran or diethyl ether at 0° to 25°C for 1 to 60 minutes and is reacted with benzoyl chloride or a lower alkyl acid chloride alternatively for 1 to 20 minutes at -100° to -70°C in, e.g., diethyl ether or tetrahydrofuran to give Compound L.

The aldehyde function is regenerated by treatment with acetone or butanone in the presence of a catalytic amount of £-toluenesu1 fontc acid or mineral acid for 1 to 24 hours at 25° to 50°C. The diazo group may then be introduced at the 4-position of the aldehyde derivative directly, or the aldehyde derivative first may be converted to the corresponding acid by procedures generally known in the art, for example, by oxidation with silver oxide or by Jones reagent or reduction to the corresponding alcohol by procedures generally known in the art, by treatment with borohydride in lower alcohols, e.g., ethanol or tetrahydrofuran at 0° to 25°C for 1 to 12 hours with subsequent introduction of the diazo group. The diazo transfer is achieved using £-toluenesulfonyl azide as described hereinabove.

EXAMPLE 11 (5a ,2OP.) -4-Diazo-3-oxopregnan-20-carboxaldehyde (2OR) -21- Ethyl enedi oxy-20-methy lpregn-4-en-3-one '2.0 a, 4.5 mmole) in tetrahydrofuran (20 ml) is added to ammonia containing aniline (420 mg, 4.5 mmole) and lithium (lOO mg, 15 mmole). After 1 hour the blue solution is treated dropwise with isoprene until the blue color dissipates. The ammonia is allowed to evaporate and the residue dried under vacuum (0.5 mm). Tetrahydrofuran (20 ml 5 is then added, the solution cooled to 0°C, and treated with a solution of trimethylsilyl chloride (4 ml) and triethylamine (4 ml) which had previously been centrifuged. After 15 minutes the mixture is diluted with pentane and washed with chilled 0.5m HCI, then chilled aqueous sodium bicarbonate, then dried (MgS0<) and concentrated. The residue is crystallized from ethy, acetate to afford 1.6 g.

To the enol ether (5a,2OR)-3-trimethylsi1oxy-21ethylenedioxy-20-methylpregn-3-ens (5.08 g, 9.8 mmole) in ether (20 ml) is added methyl lithium (5.5 ml of a 2.05 M solution, 11.3 mmole). After 1 hour at 25°C the solution is taken up in a syringe and added slowly to a solution of benzoyl chloride (1.54 g, 1.27 mmole) in ether (30 ml) at -70°C. After 5 minutes aqueous ammonium chloride is added and the products isolated by ether extraction. The residue, after evaporation of the ether, is recrystallized from chloroform-heptane to afford 450 mg.

The acetal (l g) in acetone (200 ml) containing £toluenesulfonic acid (50 mg) is stirred overnight at 25°C, then concentrated. The residue is crystallized from dichloromethane-heptane to afford the aldehyde.

The (5a,2OR )-4-benzoyl-3-oxopregnane-20-carboxaldehyde (436 mg, 1.0 mmole) in tetrahydrofuran (2.0 ml) is added to sodium hydride (48 mg, of a 50% dispersion) in tetrahydrofuran (5 ml). After 30 minutes, tosylazide (196 mg, 1.0 mmole) in tetrahydrofuran is added and the mixture stirred overnight at 25°C. Ether is then added, the mixture filtered, then washed with water, dried and evaporated. The residue is chromatographed on silica gel, the fraction eluted with 70% ether-petrol being collected. Recrystallization from chloroform-hexan affords yellow crystals (30 mg), of (5a„2OR)-4-diazo3-oxopregnane-2O-carboxaldehyde. 9 704 In the above reaction sequence TMSO means trimethylsilyl oxy.

EXAMPLE 12 To the silyl ether (5.5 g, 10 mMole) in methylene chloride (200 ml) and acetonitrile (125 ml) is added lithium tetrafluoroborate (2.8 g, 30 mMole) and the mix5 ture is stirred at room temperature for 00 hours. The mixture is then washed with water, aq. NaKC0s and aq. NaCl then dried (MgSO^ and concentrated. The residue is recrystallized from methylene-chloride-heptane to afford the alcohol (3.8 g, 86%).

Claims (11)

CLAIMS :

1. A compound of the fonnula wherein R is = 0, —OH, —0C0(C^_ 3 alkyl), —COOH, —CH 2 OH, 5 —CHO, —COO(C 1 _ g alkyl), —COCH 3 , —CH(CH 3 )—COOH, —CH(CH 3 ) —COO(C^ galkyl), 8—0—(CH 2 ) 3 —a or a 20R-isomer of —CH(CH 3 )—CH 2 OH or —CH(CH 3 )—CHO.

2. A compound as claimed in claim 1, wherein R is 8—0—(CH 2 ) 3 —a, 2OR—CH(CH 3 )—CH 2 OH, 2OR—CH(CH 3 )— 10 CHO or 20R—CH(CH 3 )—COOH.

3. A compound as claimed in claim 1, wherein R is 20R—CH(CH 3 )—CH 2 OH, 20R—CH(CH 3 )—CHO or 20R—CH(CH 3 > —COOH.

4. (5a,20R)-4-Diazo-21-hydroxy-20-methylpregnan15 3-one.

5. as described A compound as claimed in claim 1, substantially in any of the Examples.

6. A pharmaceutical composition comprising a compound as claimed in any preceding claim in association 20 with a pharmaceutically acceptable carrier.

7. A topical composition according to claim 6, which comprises from 0.001 to 5% of the compound.

8. A topical composition according to claim 7, which comprises from 0.005 to 1% of the compound. 5

9. A composition according to claim 6, substantially as described in any of the specific embodiments herein.

10. A process for preparing a compound as claimed in claim 1 when R is —CH(CH 3 )—CHO, —CH(CH 3 ) — 10 CHjOH or —CH(CH 3 )—COOH, which comprises converting 20methyl-21-oxopregn-4-en-3-one to the 21-ethylene acetal thereof; subjecting the product to reduction using lithium in ammonia, followed by reaction with trimethylsilyl chloride; reacting the resultant 20-methyl-21-oxo15 pregn-3-en-3-ol, 21-ethylene acetal, trimethylsilyl ether, with an alkyllithium and benzoyl chloride or a C 2 _ 5 alkanoic acid chloride; regenerating the aldehyde function of the product of the formula 20 wherein Z is phenyl or C^_ 4 alkyl, by treatment with acetone or butanone in the presence of a catalytic amount of £-toluenesulfonic acid; and reacting the aldehyde with sodium hydride or a tri(C 3 _^alkyl)amine and £- toluenesulfonyl azide, the aldehyde being converted to the appropriate acid or alcohol, if desired, prior to the 5 treatment with £-toluenesulfonyl azide.

11. A process as claimed in claim 10, substantially as herein described and exemplified.