Regio- and stereoselective alpha-alkylation of N-terminal amino acid residue of peptides using a pyridoxal model compound with a chiral ansa-structure

Regio- and stereoselective alpha -alkylation of N-terminal amino acid resid ue of peptides was achieved by Li+-mediated alkylation of aldimines prepare d from the peptides and a pyridoxal model compound having a chiral ansa-str ucture and an ethoxyethoxy group at C-3. The stereochemistry and stereosele ctivity of the reaction were found to be influenced predominantly by the ch irality of the model compound and Li+, but little by the stereochemistry of the original peptides. (C) 2001 Elsevier Science Ltd. All rights reserved.