syntheses are presented of the pseudo-dipeptide (3S,6S)-6-[(benzyloxy)carbonyl]amino-5-oxo-1,2,3,5,6,7-hexahydro-3-indolizinecarboxylic acid (1a) and of its (3S,6R) diastereoisomer (1b). The key step involves adding vinylogous β-enaminoester derived from pyroglutamic acid on an acrylate derivative. The 6,5-fused bicyclic lactam obtained may be viewed as a conformationally restricted Ala-Pro mimetic.
提出了伪二肽(3 S,6 S)-6-[[(苄氧基)羰基]
氨基-5-氧代-1,2,3,5,6,7-六氢-3-
吲哚嗪
羧酸(1a)及其(3 S,6 R)非对映异构体(1b)。关键步骤涉及在
丙烯酸酯衍
生物上添加衍生自焦谷
氨酸的
乙烯基β-
氨基酯。可以将获得的6,5-稠合的双环内酰胺视为构象受限的Ala-Pro模拟物。