Asymmetric Hydrogenation of Furan- containing Ketones over Tartaric Acid-modified Raney Nickel Catalyst

Abstract

The hydrogenation of b-keto esters containing a furan unit at the conjugated position to the b-carbonyl group was carried out over a chiral heterogeneous catalyst, tartaric acid-modified Raney nickel. The hydrogenation first proceeds at the carbonyl to give optically active alcohols, but a simple substrate undergoes further hydrogenation of the furan part to produce a diastereomeric mixture of alcohols having a tetrahydrofuran moiety. This overreduction was efficiently suppressed by substitutions of a substituent at the furan part. The optical yield at the hydroxy group is in the range of 40–90%.