First synthesis of (1 S,2 S)- and (1 R,2 R)-1-amino-2-isopropylcyclobutanecarboxylic acids by asymmetric Strecker reaction from 2-substituted cyclobutanones

Abstract

An efficient and easy one-pot reaction from readily available racemic 2-substituted cyclobutanones gave, by means of asymmetric Strecker synthesis in the presence of an amine chiral auxiliary, two major aminonitriles with excellent diastereoselectivity. After separation, the major cis-aminonitriles were hydrolysed and hydrogenolysed to lead for the first time to pure non-racemic (+)-1-amino-2-isopropylcyclobutanecarboxylic acid (ACBC) and its antipode.