Chiral derivative 3 was shown to be a precursor of alpha and beta -substitu
ted beta -amino acids as well as alpha,beta -disubstituted beta -amino acid
s. The key steps of the procedure are a diastereoselective alkylation of sy
nthon 3 by organocuprates reagents and a diastereoselective alkylation of t
he: alkylated adduct. (C) 2000 Elsevier Science Ltd. All rights reserved.