Abstract: (R)-1-(4-Benzyloxy-3-nitrophenyl)-2-bromoethanol, a key intermediate for the preparation of (R,R)-formoterol, was prepared from 4-benzyloxy-3-nitrophenyl-α-bromoacetophenone using BH3 complex with polymer-bonded (R)-diphenylpyrrolidinemethanol as the catalyst and NaBH4/Me3SiCl as reductant via an enantioselective reduction. The yield and ee value for the reaction are 95% and 95.4% respectively. The resulted chiral compounds can be easily separated and recycled, which reduce the production cost. Using NaBH4/Me3SiCl as the reductant could minimize the toxicity of the reaction and help to improve the safety issue.

Key words: (R)-(benzyloxy-nitrophenyl)-bromoethanol, NaBH4/Me3SiCl,enantioselective reduction,bonded (R)-diphenylpyrrolidinemethanol