New access to racemic β3-amino acids

A general simple procedure having the potential for large scale preparations of racemic β3-amino acids has been developed. The procedure involves base-catalyzed Michael-type addition of sodium diethyl malonate to N-Boc-α-amidoalkyl-p-tolyl sulfones in tetrahydrofuran. Hydrolysis of the adducts by refluxing with 6 M aqueous hydrochloric acid affords β3-amino acid hydrochlorides in high yield and excellent purity.