Crimmins Michael T, McDougall Patrick J, Emmitte Kyle A
Venable and Kenan Laboratories of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Org Lett. 2005 Sep 1;7(18):4033-6. doi: 10.1021/ol051543m.
A stereoselective synthesis of the BCDE fragment of brevetoxin A has been completed. anti-Glycolate aldol, glycolate alkylation, and ring-closing metathesis reactions were employed as key bond-forming events. A convergent assembly strategy was employed that relied on a Horner-Wadsworth-Emmons union of two complex fragments. Subsequent cyclization and dehydration led to efficient generation of an intermediate endocyclic enol ether, which was advanced to a tetracyclic fragment. [reaction: see text]
短裸甲藻毒素A的BCDE片段的立体选择性合成已完成。采用了抗乙醇酸醛醇缩合反应、乙醇酸烷基化反应和闭环复分解反应作为关键的成键步骤。采用了一种汇聚式组装策略，该策略依赖于两个复杂片段的霍纳-沃兹沃思-埃蒙斯偶联反应。随后的环化和脱水反应有效地生成了一种内环状烯醇醚中间体，该中间体进一步转化为一个四环片段。[反应：见原文]
