PSEUDO-PROLINES IN PEPTIDE-SYNTHESIS - DIRECT INSERTION OF SERINE ANDTHREONINE DERIVED OXAZOLIDINES IN DIPEPTIDES

Dipeptides containing serine and threonine derived oxazolidines are pr epared by reacting side chain unprotected dipeptides containing C-term inal Thr or Ser with dimethoxypropane. The resulting building blocks c an be coupled in Fmoc-based solid phase peptide synthesis enhancing pe ptide solvation by its secondary structure disrupting potential. The p resent procedure may be considered as a first step towards a reversibl e modification of structural and functional properties of bioactive pe ptides and proteins.