DE1062241B - Process for the preparation of derivatives of the 1,1-dimethyloctahydronaphthalene series - Google Patents

Description

According to the invention, derivatives of the 1,1-dimethyloctahydronaphthalene series are used obtained by adding the myrcene adducts obtained by diene synthesis with dienophilic compounds having the general formula

Method of manufacture

of derivatives
the 1,1-dimethyloctahydronaphthalene series

Addendum to patent 1,045,393

CO-R ₁

III

in which R ₂ to R _{4 are} hydrogen atoms, alkyl, aryl, aralkyl, cycloalkyl or heterocyclic radicals and R ₁ = OH or an ether radical, such as OCH ₃ , in a manner known per se in the presence of H. ₃ PO ₄ or BF ₃ or mixtures thereof cyclized at about -30 to + 75 ° C.

Basically the same working scheme applies as in patent 1045 393:

Applicant:
DRAGOCO

Special factory conc. Fragrances and flavorings

Gerberding & Co. G. m. B. H.,

Holzminden / Wes er

Dipl.-Chem. Dr. Günther Ohloff, Holzminden / Weser, has been named as the inventor

+ CCR ₁

II

'R.

-CR ₁
0

IV

example 1

1,1-Dimethyloctahydronaphthalene ^ -carboxylic acid methyl ester

In a solution of 224 g of esters of the general formula III (R ₁ = OCH _3; R ₂ to R ₄ = H) in 500 cc of absolute toluene was initiated with good stirring and exclusion of moisture at 0 ⁰ C Bortrinuorid. As the ring closure progressed, the temperature rose. At +18 ⁰ C, the reaction mixture was cooled again to 0 ⁰ C and then added with the remaining Bortrifluoridmenge. The total introduction time for the required 70 g of boron trinuoride was ^x / ₂ hours. Thereafter the reaction mixture to decompose the Bortrifluoridanlagerungsproduktes was so slowly with 600 cc of a 10% strength aqueous sodium hydroxide solution are added such that the temperature did not exceed +5 ^0C. The reaction solution separated into two layers. The aqueous solution was discarded and the solvent layer was washed neutral with water and then freed from toluene. The crude bicyclic ester was distilled over a short column and gave 204 g of a product which was very similar to that prepared according to Example 7. Constants:

Kp _{0, 2} = 110 to 112 ° C. D. ² ° = 1.0150; nf = 1.4941; Ester content: 99.8%.

45

Example 2
!, 1-dimethyl-carbonic acid methyl ester-octalin

300 g of esters of the general formula III (R ₁ = OCH _3; R ₂ to R ₄ = H) were added with vigorous stirring as rapidly in 1000 g of a chilled to 0 ⁰ C 85 ° / ₀ by weight phosphoric acid, that the temperature +6 Did not exceed ^{0 C.} The reaction mixture was then quickly heated to + 55 ° C. and left at this temperature for 15 minutes. Thereafter, the contents of the reaction vessel were poured onto a large amount of ice and extracted with ether. After washing the essential solution neutral with water and boiling off the solvent were

909 579/442

10

With a content of 96.7% was obtained 290 g (96 ° / _o yield) of bicyclic esters.

Constants:

Kp _{0, 4} = 118-120 ⁰ C. D. * S = 1.0060; n <g = 1.4920; Ester content: 99.7%.

The bicyclic product (formula IV: R ₁ = OCH; R ₂ to R ₄ = H) had a fine odor and consisted mainly of an isomer with the double bond either in the α-, γ- or <5-position.

Example 3

!,!, o-trimethyloctahydronaphthalene ^ -carboxylic acid methyl ester

_{80 g of ester of the general formula III (R 1} = OCH ₃ ; R ₂ and R ₃ = H; R ₄ = CH ₃ ) were added dropwise to 300 ecm of vigorously stirred 85% phosphoric acid.

Then the reaction mixture was warmed to +75 ⁰ C and vigorously stirred for a further 30 minutes at this temperature. The mixture was worked up and 78 g of the corresponding bicyclic ester of the general formula IV were obtained, from which the following constants were determined:

Bp ₀ , _e = 110 to 112 ° C; D. ^{2, 0} = 0.9816; ng "= 1.4867; ester content: 93%.

For the preparation of the starting compounds, protection is not given in the context of the present invention claimed.

The new compounds obtained by the process according to the invention are valuable fragrances represent, which are due to new and compared to known compounds by different odor notes and distinguished by particularly good adhesion compared to known octahydronaphthalene derivatives.

Claims (1)

Claim: Further development of the process for the preparation of derivatives of the 1,1-dimethyloctahydronaphthalene series according to patent 1,045,393 by cyclization of compounds of the general formula CO-R ₁ in which R ₁ to R ₄ denote hydrogen atoms, alkyl, aryl, aralkyl, cycloalkyl or heterocyclic radicals, in which, however, not all radicals R ₁ to R _{4 may} simultaneously denote hydrogen atoms, with sulfuric acid, phosphoric acid, boron trifluoride and formic acid about -30 to +75 ⁰ C, characterized in that compounds of the general formula given above, in which R ₁ is OH or an ether residue such as OCH ₃ , are used as starting materials and these are only mixed with phosphoric acid or boron trifluoride or their mixtures cyclized. > 909 579/442 7.59