摘要 |
A novel process is described for the manufacture of a mixture of 6-(2',6',6'-trimethyl-cyclohex-1'-en-1'-yl)-4-methyl-hex-3-en-1-ol and -4-en-1-ol (I) and, respectively, 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]furan, in which E,E-6-(2',6',6'-trimethylcyclohex-1'-en-1'-yl)-4-methyl-hexa-2,4-dien-1-al is reduced either with (a) lithium aluminium hydride or with (b) sodium dithionite in the presence of sodium bicarbonate in aqueous solution and of a phase transfer catalyst or with (c) sodium borohydride or with (d) sodium bis(2-methoxyethoxy)aluminium dihydride and, when reduction agent (c) or (d) is used and optionally in the case when reduction 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 results as the intermediate is reduced to the desired 6-(2',6',6'-trimethyl-cyclohex-1'-en-1'-yl)-4-methyl-hex-3-en-1-ol and -4-en-1-ol using a reduction agent (a) or (b) and, if desired, the thus-obtained compounds I are converted in a known manner into a mixture of the aforementioned furans. These furans are suitable as odorants.
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