Method for producing an optically active azolyl-.alpha. .beta.-unsaturated alcohol

A method for producing optically active alcohol derivatives represented by the formula (III) ##STR27## wherein R.sub.1 represents a C.sub.3 -C.sub.8 cycloalkyl, or a phenyl which may be substituted with a halogen, or a C.sub.1 -C.sub.4 haloalkyl, R.sub.2 represents 1,2,4-triazol-1-yl and the mark * means an asymmetric carbon, comprising asymmetrically reducing a ketone compound represented by the formula (I), ##STR28## wherein R.sub.1 and R.sub.2 have the same meanings as above, with boron hydride reducing agent modified with an optically active amino alcohol represented by the formula (II), ##STR29## wherein said modified boron hydride reducing agent is obtained by reacting a metal borohydride with a salt of the optically active amino alcohol with acid or by reacting a borane with the optically active amino alcohol, each in a molar ratio of a range from 0.3:1 to 1.2:1 and wherein R.sub.3 represents C.sub.1 -C.sub.8 alkyl or C.sub.7 -C.sub.11 aralkyl, R.sub.4 represents a hydrogen, R.sub.5 represents a hydrogen or C.sub.7 -C.sub.16 aralkyl or a phenyl which may be substituted with C.sub.1 -C.sub.6 alkoxy, and the mark * has the same meaning as above, in the presence or absence of an acid.