As part of an ongoing project concerning the synthesis of nonnatural amino acids, we have now developed a general strategy for the preparation of β2-amino acids (or 2-aminocarboxylic acid derivatives). Our procedure involves the synthesis of the sultam β-alaninate precursor 5 whose alkylation led with high yields and excellent diastereoselectivity to the precursor of β2-homophenylalanine, β2-homoalanine