α-Amino Acids as Chiral Educts for Asymmetric Products. Aminoacylation of Metallo Alkyls and Alkenyls

Article abstract of DOI:10.1021/jo00161a023

α-Amino acids have been developed as educts for the preparation of optically pure α-amino aliphatic ketones.The amino group of the L-amino acid was first blocked as a suitable acyl derivative, namely, acetyl, benzoyl, ethoxycarbonyl, or benzenesulfonyl.Then the lithium carboxylate was formed and treated with alkyl- and alkenyllithium or Grignard reagents.Thus butyl, allyl, and vinyl organometallics were added to the lithium carboxylates of L-α-N-substituted alanine, valine, O-benzyltyrosine, methionine, serine, and ε-(ethoxycarbonyl)lysine to yield the corresponding optically pure ketones, protected as amides, sulfonamides, or carbamates.