Benzoic Acid → ethyl mandelate, (S)-

Participants

Reaction Steps

A dispersion of 0.43 g (11.3 mmol) of sodium borohydride in THF (20 ml) was cooled in a cryostat at -20° C., 1.38 g (11.3 mmol) of benzoic acid was added with stirring, and the mixture was stirred for two to three minutes. A solution of diethyl L-(+)-tartrate in THF (10 ml) was then added, the mixture was stirred for five minutes, a solution of 5 g (2.8 mmol) of ethyl phenyl-glyoxylate in THF (2 ml) was further added over a period of one to two minutes, and stirring was continued for one hour. The reaction mixgture was treated in the same manner as described in Example 1, giving 0.43 g of ethyl (S)-(+)-2-hydroxy-2-phenylacetate, having specific rotation [α]D18 of +17.6° (cl. 18, CHCl3). The synthesis yield was 85% and the optical yield was 15% e.e. (see Reference 7).

Provenance & Evidence