Abstract
Synthesis of N-2, 2, 3, 3-tetrafluoropropionyl-amino acids (abbreviated as tetrafluoropropionyl- or Tfp-amino acids) by the reaction of amino acids with tetrafluoropropionyl anhydride was described. Racemization was observed to occur to a considerable extent during the process of the introduction of this group. Optically active Tfp-amino acids were able to be prepared free from racemization by transesterification of methyl tetrafluoropropionate with amino acid tert-butyl esters, followed by treatment of the resulting Tfpamino acid tert-butyl esters with trifluoroacetic acid. Some Tfp-dipeptide esters were prepared from the corresponding dipeptide tent-butyl esters in this way. This group was cleavable by mild alkaline hydrolysis or by reduction with sodium borohydrde as well as the Tfa-group.
