process for the production of diisopinocampheylchloroboran

摘要

The present invention relates to an improved process for the in situ preparation of diisopinocampheylchloroborane which comprises reacting sodium borohydride and boron trichloride with alpha -pinene. The diisopinocampheylchloroborane thus obtained may be used, without isolation, to reduce prochiral ketones to their corresponding alcohols in high optical purity.