Preparation of 6-(2,6,6-trimethyl-cyclohex-1-en-tyl)-4-methyl-hex-3-enol and -4-enol

• Main Author: HELMLINGER, DANIEL
• Format: Patent
• Language: English; French; German
• Published: 02.11.1995
• Edition: 5
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; CHEMISTRY; HETEROCYCLIC COMPOUNDS; METALLURGY; ORGANIC CHEMISTRY

A novel process is described for the preparation of a mixture of 6-(2',6',6'-trimethylcyclohex-1'-en-1'-yl)-4-methyl-hex-3-en-1-ol and -4-en-1-ol (I) or of a mixture of [3a alpha ,5a beta ,9a alpha ,9b beta ]-dodecahydro-3a,6,6,9a-tetramethylnaphtho[2,1-b]furan and [3a alpha ,5a beta ,9a alpha ,9b alpha ]-dodecahydro-3a,6,6,9a-tetramethylnaphtho[2,1-b]-fura n, with E,E-6-(2',6',6'-trimethyl-cyclohex-1'-en-1'-yl)-4-methyl- hexa-2,4-dien-1-al is reduced either using (a) lithiumaluminium hydride or using (b) sodium dithionite in the presence of sodium bicarbonate in aqueous solution and in the presence of a phase-transfer catalyst or using (c) sodium borohydride or using (d) sodium bis(2-methoxyethoxy)aluminium dihydride, and where, if the reducing agent (c) or (d) is used and, if appropriate, when the reducing agent (a) is used, the E,E-6-(2',6',6'-trimethyl-cyclohex- 1'-en-1'-yl)-4-methyl-hexa-2,4-dien-1-ol which is formed as an intermediate is reduced using a reducing agent (a) or (b) to give the desired 6-(2',6',6'-trimethyl-cyclohex-1'-en-1'-yl)-4-methyl-hex- 3-en-1-ol and -4-en-1-ol, and, if desired, the resulting compounds I are converted in a manner known per se to give a mixture of the abovementioned furans. These furans are suitable as odoriferous substances.