描述了所提出的抗癌剂立体钙蛋白 A 结构的全合成。合成有5-羟基-2,4-二甲基-3-氧代辛酸单元的具有非对称非对映选择性合成的抗-和SYN -aldol反应作为关键步骤。由于 12 元缩肽环中的独特空间限制,初始环酰胺化导致在 C-11 立体中心完全差向异构化。后期甲基化策略导致合成立体钙蛋白 A 的拟议结构。
Synthetic studies of stereocalpin A and its C5-epimer: total synthesis of 11-epi- and 5,11-diepi-stereocalpin A
摘要:
This Letter describes the synthetic studies of stereocalpin A and its C5-epimer. After various cyclization attempts, successful macrolactamization at 9-10 position was tried inorder to obtain stereocalpin A and its C5-epimer, which were accompanied by complete racemization and resulted in the synthesis of 11-epi- and 5,11-diepi-stereocalpin A. Highly functionalized octanoic acid motif of the depsipeptide was constructed by applying Paterson's aldol methodology, owing to its diversity in synthesizing various analogs of aliphatic acid. (C) 2011 Elsevier Ltd. All rights reserved.