Patent ID: 6828468
Filing Date: 2004-12-07
Classification: B01J,C07C

Abstract:
A process for preparing higher, &agr;,&bgr;-unsaturated alcohols of the formula Ia where R1 is a C1-C4-alkyl radical, R2 is hydrogen or a saturated, monounsaturated or polyunsaturated C1-C30-alkyl, cycloalkylalkyl or cycloalkyl radical which may each be substituted by C1-C4-alkyl, a) base-catalyzed monoethynylation of a ketone of the formula R1â€”COâ€”CH2â€”R2 in liquid ammonia (NH3/KOH method or NH3/MOR method), where R1 and R2 are as defined above, to the corresponding acetylene alcohol of formula Ib, b) subsequent hydrogenation of the acetylene alcohol of the formula Ib in the presence of hydrogen over a Pd-containing thin layer catalyst and c) subsequent purifying distillation of the hydrogenation product and, optionally, d) reaction of the alcohol of the formula Ia â€ƒproduced in steps a) to c) with diketene or alkyl acetoacetates of the formula IV where R5 is C1-C4-alkyl, in the presence of from 0.1 to 0.5 mol % of an organic aluminum compound, based on the alkyl acetoacetate to be reacted, to produce the corresponding methyl ketone extended by 3 carbon atoms, e) and use of the ketone obtained in step d) as starting material for steps a) to c), and wherein only a partial conversion of the ketone is achieved in step a) and the unreacted ketone is separated off in step c) and returned to step a).