Patent ID: 6025531
Filing Date: 2000-02-15
Classification: C07B,C07C

Abstract:
A process for preparing an optically active alcohol comprising reacting a prochiral ketone corresponding to the optically active alcohol and an acid with a mixture which comprises(1) a boron-containing compound selected from the group consisting ofi) a borane compound which is obtained from an optically active .beta.-aminoalcohol of the formula (I): ##STR6## wherein R.sup.1 is a hydrogen atom, a lower alkyl group or an aralkyl group which may have at least one substituent, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 represent independently a hydrogen atom, a lower alkyl group, an aryl group which may have at least one substituent, or an aralkyl group which may have a substituent, provided that R.sup.4 and R.sup.5 are different, that R.sup.1 and R.sup.5 may together form a lower alkylene group, or that R.sup.3 and R.sup.4 may together form a lower alkylene group which may optionally have a substituent or with which a benzene ring is condensed, and * stands for an asymmetric carbon atom, and a boron hydride; or obtained from said optically active .beta.-amino-alcohol (I), a metal borohydride and an acid, andii) an optically active oxazaborolidine of the formula (II): ##STR7## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and * are the same as defined above, and R.sup.6 is a hydrogen atom, a halogen atom, an alkyl group which may be substituted by at least one halogen atom, an aryl group which may have at least one substituent or an aralkyl group which may have at least one substituent, and(2) a metal borohydride.