Reactions of Chiral N-Tert-Butanesulfinyl Imines with Ethyl Nitroacetate

Abstract

The reaction of chiral N-tert-butanesulfinyl imines with ethyl nitroacetate under substoichiometric amounts of a base or an acid is studied. The best results are obtained using 0.1 equivalents of sodium methoxide in methanol. The addition takes place with high facial diastereoselectivity at the C-N stereocenter giving rise to the corresponding β-amino-α-nitroesters as an almost 1:1 diastereomeric mixture due to the easy epimerization at the α-position of the nitroester under the reaction conditions.