Highly Stereoselective Synthesis of anti-N-Protected-α-Amino Epoxides

A simple and efficient method for the synthesis of anti-N-protected amino epoxides from carbamate-protected amino acids is described. The two key steps are the monobromination of a beta-ketoester and chelation-controlled reduction of a bromomethyl ketone intermediate. Good overall yields, high diastereoselectivity, and excellent functional group compatibility are characteristic.