CH545285A - Lactones with 14 to 17 ring C-atoms - used in perfumery - Google Patents

Abstract

Lactones with 14 to 17 ring C atoms used in perfumery. Mixture of cpds. of formula:- are prepd. where peroxides of the formula R1OOR2 (where R2 is (CH2)10- -O-CHR3-CHR4-(CH2)n- H; R1 = H, hydrocarbyl, acyl or (pref) R2; R3 and R4 are both H or one is H and the other CH3; n =0-3) are decomposed with heat (80 degrees C-150 degrees C in toluene or xylene), irradiation (UV in CHCl3, CCl4 or dioxan) or chemically (e.g. reduction by variable valency of Fe, Co, Cu or nascent H). The mixture may be separated or used without separation and it may be hydrolysed.

Description

       

  
 



   The present invention relates to a new process for the preparation of bicyclic ethers of the formula
EMI1.1
 in which the symbols R d R 'denote hydrogen or one of them denotes a methyl radical and the other denotes hydrogen, which means that there is a compound of the formula on 2 ethoxycarbonylcyclododecanone
EMI1.2
 in which the symbols R and R4 have the same meaning as in formula I, analogously, the addition compound obtained is reduced to the corresponding carbinol, the latter is saponified and decarboxylated in an alkali solution and the like. the resulting keto alcohol is cyclized with an acidic cyclizing agent or a halogen.



   In Swiss Patent No. 523 879 there is a process for the production of bicyclic ethers of the formula
EMI1.3
 in which R and R4 denote hydrogen or one of them denotes a methyl radical and the other denotes hydrogen and n denotes an integer from 0 to 3, and in which the sum of the ring carbon atoms is 14 to 17, which are prepared by known methods according to the reaction scheme below, mentioned.
EMI2.1
  



   The bicyclic ethers of the formulas I and III are starting materials for the production of lactones of the formula
EMI3.1
 and the corresponding unsaturated lactones of For
EMI3.2
 in which m denotes the number 1 or 2.



   It has now been found that the bicyclic ethers of the formula I can be prepared with good yields by using the method according to the invention.



   According to a preferred procedure, the reduction to carbinol is carried out using sodium borohydride. As acidic cyclizing agents, mineral or organic acids, e.g. Hydrochloric acid, phosphoric acid, sulfuric acid. Use benzenesulfonic acid, p-toluenesulfonic acid or trifluoroacetic acid, or acidic diatomaceous earths. Halogens, e.g. Iodine, are also suitable as cyclizing agents. The cyclization can be carried out by dissolving the compound to be cyclized in the presence of the cyclizing agent in an inert organic solvent, e.g. in an aliphatic, cycloaliphatic, aromatic, araliphatic or chlorinated hydrocarbon, or in an ether, e.g.

  Di oxane, tetrahydro urane or monoglyme, carried out according to a preferred procedure, an acidic diatomaceous metal is used as the cyclizing agent and hexane as the inert organic solvent.



   The 2-ethoxycarbonyl cyclododecanone used as starting material can be obtained from cyclododecanone. a cheap commercial product, according to known methods (see e.g.



   Tetrahedron, 19, 1625 f1963j).



   The synthesis of the bicyclic ethers I is illustrated by the reaction scheme below.
EMI3.3
  



   In this scheme, the symbols R8 and R4 have the same meaning as in formula I.



   In the following exemplary embodiment, the temperatures are given in degrees Celsius.



   example
A solution of acrolein (196 g) in 300 ml of methanol was added dropwise at 0-30 to a vigorously stirred solution of 763 g of 2-ethoxycarbonyl-cyclododecanone (3 mol) and 15 g of sodium methylate in 2 liters of methanol (1 1/2 hours). The reaction mixture was then left to stand at 0 for a further 30 minutes. The 2-ethoxycarbonyl-2- [3-oxo-propyl-cyolododecanone obtained in this way was not isolated from the reaction mixture but was used for the next stage of the process without prior purification.



   30 g of sodium borohydride (0.79 mol) were added to the above mixture in portions with stirring at 0-30, and the solution was kept at this temperature until it had completely disappeared by thin-layer chromatography (SiO2, Jlenzoi / ethyl acetate 9: 1) of the starting material observed.



   330 ml of a 30% strength aqueous solution of sodium hydroxide (3.3 mol) were added to the above reaction mixture with vigorous stirring over the course of 20 minutes. The temperature, which was 0 at the beginning of the reaction, rose to 200 and was then increased to 65-700 by means of a water bath. The mixture was kept at this temperature for 3 hours and the sodium hydrogen carbonate (230 g) which precipitated during the above operation was isolated by filtration. After evaporation of the volatile constituents, a residue was obtained from the clear filtrate, which was diluted with 4 liters of water and extracted with 2 liters of toluene.

  After the usual treatment (washing with 4 liters of water, neutralization with 200 ml of 25% strength sulfuric acid and drying), 740 g of crude product were obtained from the organic phase by evaporation. The subsequent fractional distillation of the crude product gave 609 g of 2 [3-hydroxypropyl] cyclododecanone, boiling point 115-160-1650C / 0.1 Torr.



  The product obtained in this way was used for the next process stage without prior purification. IR: 3420, 1700 cm-,
309 g of 2- [3-hydroxypropyl] cyclododecanone in 1000 ml of n-hexane were treated with 60 g of acidic diatomaceous earth. The reaction vessel was fitted with a side distillation apparatus in order to enable direct distillation of the water formed during the reaction. 46 ml of water was collected. After cooling, the suspension was filtered and the solid was washed with hexane.

 

   Evaporation of the volatile constituents gave 600 g of residue which was subjected to fractional distillation. In this way, 510 g of 13-oxa-ticyclo [10.4.0] hexadecn- [1112)], boiling point 116120 / 0.1 Torr were obtained. IR: 1660 cm-1.



   If you use methacrolein or



  Methyl vinyl ketone used instead of acrolein gave 15-methyl-13-oxabicyclo [10.4.0] hexadecene - [1 (12)] or 14-methyl-13-oxabicyclo [10.4.0] hexadecene 41 (12)], which had the following analytical constants: 15-methyl-13-oxabicyclo [10.4.0] hexadecene [1 (12)]: d20 = 0.9623; nD20 = 1.5018, 14-methyl-13-oxabicyclo [10.4.0] hexanedecene [1 (12)]: d420 = 0.9581; nD20 = 1.5037.


    

Claims (1)

P A T E N T A N S P R U C H Process for the preparation of compounds of the formula EMI4.1 in which the symbols R and R4 denote hydrogen or one of them denotes a methyl radical and the other denotes hydrogen, indicating that 2 ethoxycarbonylcyclododecanone is a compound of the formula EMI4.2 in which the symbols R and R4 have the same meaning as in formula I, is added, the addition compound obtained is reduced to the corresponding carbinol, the latter ripens and decarboxylates in an alkali solution and the keto-alk erhaltenenhol obtained is cyclized with an acidic cyclizing agent or a halogen SUBCLAIMS 1. Process according to patent claim, characterized in that the cyclization is carried out by means of a mineral or organic acid or an acidic diatomaceous earth in an inert organic solvent. 2. The method according to claim, characterized in that the addition compound is reduced to the corresponding carbinol by means of sodium borohydride,