The stereoselective reduction of bromomethyl ketones derived from leuc
ine, phenylalanine, alanine and valine is described using borohydride
reagents. The Boc-amino alcohol product has erythro stereochemistry at
the carbinol center as deduced by conversion to Boc-amino epoxides. T
hese oxiranes are useful for the preparation of hydroxyethylene peptid
e isosteres.