Acetaldehyde → 2-Phenylethanol

Participants

Reaction Conditions

Reaction Steps

Triphenylphosphine (8.4 g.) and potassium carbonate (4.9 g.) were added to a stirred solution of 2-[p-(2-bromoethyl)phenyl]ethyl tetrahydropyranyl ether (10 g.) in acetonitrile (200 ml.) and the mixture was heated under reflux for 36 hours, cooled and filtered. The filtrate was evaporated to dryness and the residue was purified by chromatography on a silica gel column using a 10:1 v/v mixture of methylene chloride and methanol as eluant. n-Butyllithium (1.2 ml. of a 1.5 molar solution in hexane) was added to a stirred solution of the phenethyltriphenylphosphonium bromide thus obtained (1.1 g.) in tetrahydrofuran (5 ml.) which was maintained at -40° C. under an atmosphere of argon, and a solution of the above acetaldehyde (0.2 g.) in tetrahydrofuran (5 ml.) was added. The reaction mixture was stirred at -40° C. for 18 hours, allowed to warm up to laboratory temperature and saturated aqueous ammonium chloride solution (10 ml.) was added. The mixture was extracted three times with diethyl ether (10 ml. each time) and the combined extracts were washed with water, dried and evaporated to dryness. The residue was purified by chromatography on a silica gel column using a 3:1 v/v mixture of petroleum ether (b.p. 40°-60° C.) and diethyl ether as eluant. The product thus obtained was hydrogenated over a palladium- on-charcoal catalyst by a similar process to that decribed in the second part of Example 3, and the tetrahydropyranyl group was removed by acidic hydrolysis by a similar process to that described in the fifth paragraph of Example 2. There was thus obtained as an oil 2-p-{4-[(1RS, 2SR)-6-methoxy-2-p-methoxyphenyl-1,2,3,4-tetrahydronaphth-1-yl]butyl}(phenylethanol.

Provenance & Evidence