N-Nitroso-L-4-hydroxyproline as a precursor of intermediates for peptide synthesis

Abstract

The N-nitroso derivative of L-4-hydroxyproline has been converted into various esters and other intermediates intended for use as coupling components in peptide synthesis. The preparative approach involved selective acidic cleavage of nitroso in the presence of different carboxyl-protecting groups, including the acid-labile 2,4,6- trimethylbenzyl moiety. Practical application of the new intermediates was illustrated by representative syntheses of crystalline protected L- 4-hydroxyproline peptides.