AZIDO ACIDS IN A NOVEL METHOD OF SOLID-PHASE PEPTIDE-SYNTHESIS

Azido acids were produced from alpha-branched acids by alpha-brominati on with NBS followed by substitution with sodium azide and the product s were used in a novel method of solid-phase synthesis. The azido acid s were transformed into the highly activated acid chlorides and used s ynthesis of extremely hindered peptides containing up to four successi ve diphenyl glycine or Aib residues. By reaction of the genetically en coded amino acids with TfN(3) and then SOCl2 they were transformed int o alpha-azido acid chlorides used in solid-phase peptide synthesis wit hout racemization. (C) 1997 Elsevier Science Ltd.