A New Strategy for the Preparation of 3‐Amino‐4‐hydroxypyrrolidinone‐4‐acetic Acid, an Unusual γ‐Amino Acid found in Microsclerodermins

Abstract

AbstractAn original synthetic strategy is presented for the preparation of the sensitive 3‐amino‐4‐hydroxypyrrolidinone‐4‐acetic acid residue that is present in the structures of the microsclerodermin natural product family. The approach relies on the use of a linear γ‐amino acid surrogate, derived from asparagine, bearing a β‐dithiolanyl group. A protected dipeptide model system is used to demonstrate that selective removal of the dithioketal protection followed by cyclization gives the target structure in single diastereoisomer form and with little or no dehydration.