摘要:
Protected versions of (3R,SR)-5-hydroxypiperazic acid were synthesized enantioselectively in two novel ways. The first derives its chirality from D-glutamic acid while the second uses an Evans amination and a diastereoselective bromolactonization to establish the two chiral centers. Given that this amino acid is a component of several depsipeptides, these two routes enable the synthesis of multigram quantities of protected versions of 2. (C) 2000 Elsevier Science Ltd. All rights reserved.