DD295372A5 - PROCESS FOR THE PREPARATION OF FENCHOLENE DEHYDE DERIVATIVES - Google Patents

Abstract

The invention relates to a process for the preparation of unknown Fencholenderivaten which are oxygen-functionalized in Fuenfring. The invention has the object, starting from easily representable from a-pinene oxide via fencholenaldehyde epoxide of Fencholenaldehyddioxolans represent previously unknown in the cyclopentane ring oxygen-functionalized Fencholenderivate, which are themselves components for fragrance mixtures or are modifiable to such. The object is achieved in that fencholenaldehyde is epoxidized by known methods and the epoxide is isomerized with zinc bromide to the keto compound or with aluminum tri-isopropylate to allyl alcohol, which can be converted to ethers and esters that can be easily modified to perfume mixture components. Equations {Fencholenverbindungen; Fencholenepoxid; Oxofencholenaldehyd; Hydroxyfencholenaldehyd; Fencholenylether; Fencholenylester; Trimethylcyclopentanone; Trimethylcyclopentanole}

Description

Anwondungsbolsplole

2 [(2,2,4-tri-methyl-1-3-OXO-CVcio-oct-1-yl) -othyl] -1,3-dioxol-Bn

5.3 g (0.026 mol) of 2-l3,4-epoxy-2,2,4-trimethyl-cyclopent-1-yl) -mobilbyl] -1,3-dioxolane are mixed with 200 mg of freshly molten zinc bromide in 50 ml of toluene for 3 hrs. heated to reflux. After cooling, it is stirred with water for 30 minutes at room temperature. The organic phase is separated, washed with Wossor dried over Na ₂ SO ₄ . The solvent is evaporated I.Vac

and the residue i. Vak. fractionated. This gives 4 g (70% of theory) of colorless oil. Purity 95% (GC) bp: 80-82 ° C / 0.5 Torr, ng ⁰ : 1.4747, IR Film: 1147 (CO-), 1734 (> C = 0) cm- ¹ , MW: 212 (MS).

2- [3-hydroxy-2,2-dimQthyl-4-mothylen-cyclopont-1-yl) mothyl] -1,3-dloxolan

5.3 g (0.025 mol) of 2 ((3,4-epoxy-2,2,4-trimethylcyclopent-1-yl) methyl] -1,3-dioxolane are refluxed in 30 ml of toluene with 0.4 g of aluminum isopropylate for 4 hrs The mixture is then each stirred with 5% strength aqueous sulfuric acid and then with water for 30 minutes at room temperature.The organic phase is separated off and dried over Na ₂ SO _4. After evaporating off the solvent, the residue is fractionated in vacuo. 1 g (77% of theory) colorless oil, purity: 97% (GC), b.p. 101-103 ° C / 0.5 torr, ng ⁰ : 1.4929, IR (film): 1148 (CO -), 1660 (-C = C-), 3074 (= CH), 3470 cm ^-1 (-OH).

2 - [(3-hydroxy-2,2,4-trlmethyl-cyclopent-1-yl) methyl] -1,3-dioxolane

a) 12g (0.056mol) of 2 - ((3-hydroxy-2,2-dimothyl-4-methylene-cyclopent-1-yl) methyl] -1,3-dioxolane 150mL η-hexane with PtO ₂ until ingested hydrogenated from 1200 ml of hydrogen, the catalyst is filtered off, the solvent is evaporated off and the residue is fractionated in vacuo, giving 11.5 g (96% of theory) of colorless oil.

Bp: 155-158 ^e C / 3 Torr, ng ⁰ : 1.4768, IR (FI): 1054 (CO), 1151, 3475 cm ^-1 (-OH).

b) 4 g (0.019 mol) of 2 - [(3-hydroxy-2,2-dimethyl-4-methylene-cyclopent-1-yl) methyl] -1,3-dioxolane in 20 ml abs. Ethers are added to a slurry of 0.25 g (0.006 mol) of LiAlH ₄ in 30 ml abs. Ether dropped. It is left for 4 hours. boil at reflux, cooled to ⁰ ° C, hydrolyzed by addition of water and dissolves the precipitate with 10% sulfuric acid. The organic phase is separated, the aqueous extracted twice more with ether. The combined organic phases are washed neutral and dried with Na ₂ SO ₄ . After evaporation of the solvent and fractionation i. Vak. 3.5 g (88% of theory) of colorless oil are obtained. (Data as under a).

2 - [(3-acyloxy-2,2-dimethyl-4-mothylen-cyclopent-1-yl) methyl] -1,3-dioxolane (A) and 2 - [(3-acyloxy-2,2,4-trimothyl cyclopent-1-yl) methyl, 3-dloxolanes (B)

General procedure: 0.019 mol of the unsaturated or saturated alcohol are mixed with 2 g (0.025 mol) of pyridine and 0.025 mol of acid anhydride in 20 ml of dichloromethane for 4 hrs. heated to reflux. It is allowed to stand overnight, treated once with 15% hydrochloric acid and twice with water. It is then dried with Na ₂ SO ₄ , the solvent is evaporated off and distilled in vacuo. Physical data (acid anhydrides used (R-CO) ₂ O]

A Sdp. ° C / Torr ng ⁰ B Sdp.X / Torr ng ⁰ R % Yield. 112-115 / 0.2 1.4782 % Yield. 95-98 / 0.25 1.4692 CH ₃ 88 95-96 / 0.2 1.4806 90 , 94-96 / 0.2 1.4654 C ₂ H ₆ 69 104-106 / 0.25 1.4733 69 96-110 / 0.25 1.4630 nC ₃ H ₇ 60 997-99 / 0.2 1.4714 70 106-108 / 0.3 1.4610 ! C ₃ H ₇ 60 75

Claims (2)

1. A process for the preparation of new in the cyclopentane ring oxygenated Fencholenderivate, characterized in that the trans-a-pinene readily accessible fencholenaldehyde is converted in a conventional manner by reaction with ethylene glycol with addition of acid in the glycol acetals, with 40% peracetic acid to the trans Oxidized epoxides or that are formed from the Aldehyj in a conventional manner by aldol condensation with carbonyl compounds and subsequent reduction and hydrogenation, the Cyclopentenylalkanole which are oxidized with 40% pure acetic acid to the trans-epoxides and that of these Epoxyfencholenverbindungen in an inert solvent be reacted with a metal halide as Lewis acid catalyst to give 1-substituted 2,2,4-trimethylcyclopentan-3-one compounds, which result by reduction with LiAIH _4, the cyclopentanols obtained by reaction with acyl anhydrides or acyl chlorides in dichloromethane in the presence v are reacted on pyridine in the esters or that the epoxy-crepes are reacted in an inert solvent with a metal alkoxide catalyst to 1-substituted 2,2-dimethyl-4-methylene-cyclopentan-3-ol compounds by reduction with hydrogen Platinum in η-hexane give the cyclopentanols, which are converted as above into the esters and ethers. 2. The method according to claim 1, characterized in that are used as the inert solvent toluene, as the metal halide anhydrous zinc bromide and as Metallalkoholat anhydrous Aluminiumtriisopropylat. Field of application of the invention The invention relates to a process which allows, in a simple manner, the first-time preparation of acid-functionalized fencholenium compounds which are starting materials for the recovery of numerous derivatives which are of importance for perfume mixtures. Characteristic of the known state of the art From a-pinene on a-pinene oxide representable a-Campholen- and Fencholenverbindungen oind suitable starting materials for the production of fragrances. Because of woody and especially sandalwood-like odor notes, the reaction products of a-campholenic and fencholenaldehyde are particularly interesting [K. SCHULZE, H. UHLIG; Monatsh. Chem. 1989, 120, 547 and literature cited therein). However, while the sidechains in the α-camphorene and fencholenic compounds have been varied widely, modifications in the methylated cyclopentene ring are not known. Object of the invention The invention aims to provide access to the hitherto unknown cyclopentanone and cyclopentanol derivatives of the fencholene series. Presentation of the essence of the invention The object of the invention is to prepare ketones and alcohols as oxygen-functionalized perfume mixture components of epoxyfencholene aldehyde derivatives in the cyclopentene part of the fencholene system. The object is achieved in that the representable from a-pinene via a-pinene fencholenaldehyde is first protected by Acetalbifdung or aldol condensation against further oxidation and then the Cycfopentendoppelbindung is oxidized with 40% peracetic acid in dichloromethane to the epoxide and these epoxy compounds by heating with anhydrous zinc bromide in toluene to the 2,2,4-trimethyl-cyclopentan-3-one compounds are reacted, which can be reduced with lithium aluminum hydride in ether to the cyclopentanols from which with acyl anhydrides in dichloromethane in the presence of pyridine, the corresponding esters can be represented or in that the 3,4-epoxy compounds are reacted by rolling with aluminum triisopropylate in toluene to give the 2,2-dimethyl-4-methylenecyclopentane-1-ols which, directly or after hydrogenation with hydrogen on platinum contact with acylanhydrides in dichloromethane and pyridine can be esterified or via tosylate with Alcoholates in ethanol give the cyclopentanyl ethers. The reaction will be demonstrated by examples.