Diastereoselective reduction of ketimines derived from (R)-3,4-dihydroxybutan-2-one: an alternative route to key intermediates for the synthesis of anticancer agent ES-285

A simple and convenient procedure for the diastereoselective reduction of imines derived from (R)-3,4-dihydroxybutan-2-one is described. The use of sodium borohydride as a reducing agent in the reactions with pre-synthesised imines gave aminodiol derivatives with the appropriate stereochemistry for use as intermediates in the synthesis of anticancer agent ES-285. The aminodiols were isolated in ca. 62% yield.