Short asymmetric synthesis of (2S,3S)- and (2S,3R)-3-prolinoglutamic acids: 2-carboxy-3-pyrrolidine-acetic acids (CPAA)

The asymmetric synthesis of both cis and trans 3-prolinoglutamic acids can be easily achieved in a diastereoselective and enantioselective way via the amino–zinc–enolate cyclisation.