A new process was described for the preparation of t-butyl (3R,5S)-6-hydroxy-3,5-O,O-isopropylidenedioxyhexanoate, which is a key intermediate for a number of HMG-CoA reductase inhibitors. The intermediate was easily and efficiently obtained under mild reaction conditions via two enantioselective hydrogenation reactions with a high di-astezeoselectivity of 99% de in an overall yield of 38% for the eight-step procedure.

Key words: protecting group, enantioselective hydrogenation, industrialization