New Approach to the Coupling of γ-Amino β-Hydroxy Acids and β,γ-Dihydroxy Acids with α-Amino Acid Esters
摘要:
alpha,alpha-Dichloro beta-lactones, readily obtained by a highly diastereoselective cycloaddition of dichloroketene to N-Boc-alpha-amino aldehydes and alpha-(silyloxy) aldehydes, coupled efficiently with alpha-amino acid esters leading, after dehalogenation with H-2 over 10% Pd on charcoal, to peptide mimics under mild reaction conditions.