SYNTHESIS OF CASEIN-RELATED PEPTIDES AND PHOSPHOPEPTIDES .5. THE EFFICIENT GLOBAL PHOSPHITE-TRIESTER PHOSPHORYLATION OF PROTECTED SERINE DERIVATIVES AND PEPTIDES BY USING DIBENZYL OR DI-TERT-BUTYL N,N-DIETHYLPHOSPHORAMIDITE

Both dibenzyl N, N-diethylphosphoramidite and di-t-butyl N, N-diethylphosphoramidite are shown to be suitable reagents for the efficient lH-tetrazole-catalysed ‘phosphite-triester’ phosphorylation of the protected serine derivative Boc-Ser-OCH2C6H4NO2-p. Both these reagents were also used for the phosphorylation of the protected serine derivative Boc-Glu(OBut)-Ser-Leu-OBut, and subsequent hydrogenolytic treatment of Boc-Glu(OBut)- Ser(P03Bzl2)-Leu-OBut or acidolytic treatment of Boc-Glu(OBut)-Ser(POsBut2)-Leu-OBu' gave the O-phosphoseryl tripeptide Glu-Ser(PO3H2)-Leu in near-quantitative yield. © 1990 ASEG.