Highly efficient enantiospecific synthesis of imidazoline-containing amino acids using bis(triphenyl)oxodiphosphonium trifluoromethanesulfonate.

A highly efficient enantiospecific synthesis of imidazoline-based amino acids is reported from dipeptides composed of a C-terminal beta-amino-alpha-amino acid residue using bis(triphenyl) oxodiphosphonium trifluoromethanesulfonate. These imidazolines were easily converted to imidazoles and incorporated into macrolactam analogues of bistratamide H without loss of stereochemical integrity.