The formaltotalsynthesis of stevastelinsB and B3 (2 and 4, resp.) have been accomplished employing a highly enantiomerically controlled Lewis acid catalyzed non‐aldol approach to obtain the syn aldol product and temperature controlled hydroboration oxidation reaction to construct four consecutive stereogenic centers. The other key reactions include Sharpless asymmetric epoxidation, macrolactonization
Total synthesis of (–)-stevastelin BElectronic supplementary information (ESI) available: experimental details. See http://www.rsc.org/suppdata/cc/b2/b202298b/
作者:Kazuo Kurosawa、Toshihiko Nagase、Noritaka Chida
DOI:10.1039/b202298b
日期:2002.5.30
The total synthesis and an unambiguous structure confirmation of stevastelin B 1, a novel 15-membered cyclic depsipeptide, are described; the fatty acid moiety in 1, prepared stereoselectively from L-quebrachitol was converted into the amino carboxylic acid, whose macrolactamization by Shioiriâs procedure effectively constructed the cyclic structure of 1.
关于新颖的15元环状缩肽stevastelin B 1的全程合成及其明确结构确认的描述如下:通过从L-白梨醇选择性制备的脂肪酸部分,转化为氨基酸羧酸,按照Shioiri的程序进行大环内酰胺化,有效地构建了1的环状结构。
Total Synthesis of Stevastelin B, a Novel Immunosuppressant
作者:Naoki Kohyama、Yukio Yamamoto
DOI:10.1055/s-2001-13382
日期:——
Total synthesis of stevastelin B is described. Evans asymmetric aldol methodology and Roush asymmetric allylation were used to construct four consecutive stereo-centers on the octadecanoic acid moiety of stevastelin B. Subsequent coupling with a dipeptide and macrolactamization gave stevastelin B. The flexibility of this route could allow the synthesis of many analogues for biological tests, which cannot be obtained from natural sources.
本文介绍了甜叶菊苷 B 的全合成。利用伊文思不对称醛醇法和鲁什不对称烯丙基化法在十八烷酸分子上构建了四个连续的立体中心。
A synthesis of the stevastelins. a novel class of immunosuppressant agents, is reported based on a macrolactonization approach. This synthesis commenced with the stereoselective preparation of the stearic acid segment from tetradecanal using Evans asymmetric synthesis methodology and an aldol reaction with a thioester. After a high yielding coupling reaction between the fatty acid residue and the corresponding tripeptide. we proceeded with the macrolactonization key step. Thus, macrolactonizations of hydroxy acid 27 and dihydroxy acid 30, according to Yamaguchi conditions, afforded the corresponding 13-membered ring stevastelin derivatives 28 and 31 in 90 and 82% yields, respectively. In this latter case, the corresponding 15-membered lactone was not formed. Finally. depsipeptide derivative 31 was converted into stevastelin C3 (5). (C) 2002 Elsevier Science Ltd. All rights reserved.