用烯丙醇/ Ti(OR)4加热非对映异构纯N-酰基磺酰胺3或4,可有效产生阿磺胺1或2和烯丙基酯5。在威尔金森氏催化剂的存在下,在非碱性条件下将酯5水解,得到对映异构和非对映异构纯的羧酸7。因此,由N- [ N '-(Fmoc)氨基]酰基苏丹酰胺12制备了一系列[[芴-9-基)甲氧基]-羰基-(Fmoc)-保护的氨基酸14。
A novel DMAP-promoted oxazolidinethione deacylation. Application for the direct conversion of the initial chiral thioimide aldols to various ester protecting groups
摘要:
DMAP (4-(dimethylamino)pyridine) promoted nucleophilic cleavage of the initial chiral thioimide aldols can be directed to form various ester protecting groups without causing racemization of the newly created stereocenters. (C) 1999 Elsevier Science Ltd. All rights reserved.