Manipulation of the cabboxyl groups of α-amino-acids and peptides using radical chemistry based on esters of [formula omitted]-hydroxy-2-thiopyridone

Abstract

Photolysis of α-amino-acid or peptide esters derived from N -hydroxy-2-thiopyridone in the presence of t -butylthiol affords the expected decarboxylation products in good yield. The reaction can be applied to the α-carboxyl or to the side chain carboxyl of glutamic and aspartic acids and thus permits the preparation of a number of useful synthons. Photolysis of side chain esters in the presence of a suitable halogen atom transfer reagent gives halides often in good yield and, especially in the case of aspartic acid derivatives, without racemisation.