Enantioselective Total Syntheses of Allopumiliotoxins 267A, 323B‘, and 339A. Application of Iodide-Promoted Iminium Ion−Alkyne Cyclizations for Forming Allopumiliotoxin A Alkaloids
作者:Christian Caderas、Renee Lett、Larry E. Overman、Michael H. Rabinowitz、Leslie A. Robinson、Matthew J. Sharp、Jeffery Zablocki
DOI:10.1021/ja961640y
日期:1996.1.1
The first synthesis of (+)-allopumiliotoxin 323B‘ (4) rigorously confirms the complete stereostructure of 4 and establishes that the major C(15) epimer isolated from dendrobatid frogs has the 15S configuration. The total synthesis of 4 was realized in 5 steps and 17% overall yield from alkyne 39 and aldehyde 20; the synthesis proceeded in 13 steps and 6% overall yield from (S)-2-methyl-1-penten-3-ol and
描述了一种用于 allopumiliotoxin A 生物碱全合成的简洁、立体控制的策略。Enantiopure (+)-allopumiliotoxin 267A (3) 的第二代全合成在 10 个步骤中完成,来自市售的恶唑烷酮前体醇 32 和 17 个步骤的总产率为 11%,N-[(3) 的总产率为 4%。苄氧基)羰基]-1-脯氨酸。(+)-allopumiliotoxin 323B' (4) 的首次合成严格证实了 4 的完整立体结构,并确定从 dendrobatid 青蛙中分离出的主要 C(15) 差向异构体具有 15S 配置。4的全合成分5步实现,炔烃39和醛20的总收率为17%;从 (S)-2-methyl-1-penten-3-ol 合成 13 步,总产率为 6%,17 步和 3。