Synthesis of dehydroamino acids and didehydrodioxopiperazines and their conversion into α‐mercapto‐α‐amino acid derivatives

Abstract

AbstractA synthesis of α,β‐dehydroamino acid derivatives 12 is described, which is of possible general applicability and might be useful for the preparation of peptides which have such a moiety in their sequence. In addition, several didehydrodioxopiperazines (13–17) have been prepared. The reactivity of these compounds towards liquid H2S in the presence of ZnCl2 has been studied. Only the dehydroalanine derivatives 12a and 13 gave α‐addition products; all other dehydroamino acid derivatives and cyclic dipeptides failed to react cleanly.