Diastereoselective Total Synthesis of (±)-Schindilactone A, Part 3: The Final Phase and Completion
Diastereoselective Total Synthesis of (±)-Schindilactone A, Part 3: The Final Phase and Completion
复制标题
DOI：
10.1002/asia.201200365
复制
发表时间：
2012-10-01
影响因子：
4.1
通讯作者：
Yang, Zhen
中科院分区：
文献类型：
--
作者：
Ren, Wei-Wu;Chen, Zhi-Xing;Yang, Zhen
本文描述了全合成(+/-)-五味子内酯A(1)的最终阶段。发展了两种独立的合成方法，分别是Pdthiourea催化的级联羰基化环化反应生成中间体3和RCM反应生成中间体4。其他重要的合成步骤包括：1)由二溴环丙烷30经Ag催化的扩环反应生成溴乙烯17；2)Pd催化的溴乙烯17与铜烯醇的偶联反应合成酮酸酯16；3)RCM反应由双烯11生成二氧双环克隆烯醇10；4)通过高硫脲催化的PausonKhandd反应在底物8中构建环戊酮片段；5)Dieckmann型缩合反应成功地形成了五味子内酯A(1)的A环。为全合成五味子内酯A(1)而开发的化学方法将为合成五味子内酯A的其他家族成员提供帮助。
The final phase for the total synthesis of (+/-)-schindilactone A (1) is described herein. Two independent synthetic approaches were developed that featured Pdthiourea-catalyzed cascade carbonylative annulation reactions to construct intermediate 3 and a RCM reaction to make intermediate 4. Other important steps that enabled the completion of the synthesis included: 1) A Ag-mediated ring-expansion reaction to form vinyl bromide 17 from dibromocyclopropane 30; 2) a Pd-catalyzed coupling reaction of vinyl bromide 17 with a copper enolate to synthesize ketoester 16; 3) a RCM reaction to generate oxabicyclononenol 10 from diene 11; 4) a cyclopentenone fragment in substrate 8 was constructed through a Cothiourea-catalyzed PausonKhand reaction (PKR); 5) a Dieckmann-type condensation to successfully form the A ring of schindilactone A (1). The chemistry developed for the total synthesis of schindilactone A (1) will shed light on the synthesis of other family members of schindilactone A.