Patent ID: 6342644
Filing Date: 2002-01-29
Classification: C07B,C07C

Abstract:
A method for producing 1-menthol represented by a formula (7), which comprises:hydrogenation of piperitenone represented by a formula (1) with a complex of an optically active phosphine represented by a general formula (2) wherein R1 represents an aryl group which may have a substituent group or a cycloalkyl group having from 3 to 8 carbon atoms and a transition metal,or a complex of an optically active phosphine represented by a general formula (3) wherein R1 represents an aryl group which may have a substituent group or a cycloalkyl group having from 3 to 8 carbon atoms and a transition metal,or a complex of an optically active phosphine represented by a general formula (4) wherein R1 represents an aryl group which may have a substituent group or a cycloalkyl group having from 3 to 8 carbon atoms, R2 represents hydrogen atom or a lower alkyl group having from 1 to 4 carbon atoms, R3 represents hydrogen atom, methyl group, methoxy group or a halogen atom, and R4 represents methyl group or methoxy group, or R3 and R4 together form methylenedioxy group and a transition metal,thereby producing pulegone represented by a formula (5), hydrogenation of the resulting pulegone with a ruthenium-phosphine-amine complex in the presence of a base, thereby obtaining pulegol represented by a formula (6) and further hydrogenation of the pulegol with a transition metal catalyst.