作者:Troy Lister、Michael V. Perkins
DOI:10.1071/ch04039
日期:——
stereocentres and alkylation of an Evans’ auxiliary to generate the remote side-chain 3R stereocentre. Furthermore, a novel, highly efficient, and selective strategy was used to generate an enol trimethylsilyl ether whose subsequent Mukaiyama aldol condensation gave the acyclic precursor to the final product. A thermodynamically controlled cyclization then gave (2S,3R,5R,6S)-6-[(1E,3R)-1,3-dimethylh
(2S,3R,5R,6S)-6-[(1E,3R)-1,3-dimethylhex-1-enyl]-2-ethyl-2-hydroxy-3,5-dimethyltetrahydro-4H 的高度立体控制合成-pyran-4-one 已通过 13 个步骤实现,(R)-(+)-4-benzyloxazolidin-2-one 的总产率为 7.6%。这种由底物控制的不对称合成利用 Paterson 的乳酸衍生的手性酮 (2S)-2-(苯甲酰氧基) 戊-3-one 生成 5R 和 6S 立体中心,并通过 Evans 辅助剂的烷基化生成远程侧链 3R 立体中心. 此外,使用一种新颖、高效和选择性的策略来生成烯醇三甲基甲硅烷基醚,其随后的 Mukaiyama 醛醇缩合得到最终产物的无环前体。然后热力学控制的环化得到 (2S,3R,5R,6S)-6-[(1E,3R)-1,3-dimethylhex-1-e