APPLICATION OF TETRALINYLS AS CARBOXAMIDE PROTECTING GROUPS IN PEPTIDE SYNTHESIS

Abstract

. I-Tetralinylamines were used as precursors to prepare the carboxamide protected derivatives of asparagine (lb-5b) and glutamine (la-Sa). The carboxamide protected derivatives were then subjected to cleavage studies in trifluoroacetic acid¬dichloromethane-anisole at 25 •C. All the glutamine carboxamide protecting groups were completely removed within 24 hours, however, only 5-methoxy-I,2,3,4-tetrahydro-1- naphthyl and 6-methoxy-1,2,3,4-tetrahydro-l-naphthyl groups of the asparagine derivatives were removed. Boron tristrifluoroacetate (BTFA)-trifluoroacetic acid (TFA) removed all the carboxamide protecting groups in glutamine and asparagine derivatives within 24 hours. These asparagine derivatives whose protecting groups were not removed by TFA were then used to synthesize the dipeptides and tripeptides.