An enantioselective total synthesis of the marine tricyclic polyketide ascospiroketal B, previously isolated from the marine-derived fungus Ascochyta salicorniae, was accomplished in 21 steps by using an improved route. The intriguing 5,5-spiroketal-cis-fused-γ-lactone core was constructed through rearrangement of an epoxide, in conjunction with an acid-mediated spiroketalization.

中文翻译：

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Ascospiroketal B 的全合成

以前从海洋来源的真菌 Ascochyta salicorniae 中分离出来的海洋三环聚酮化合物 ascospiroketal B 的对映选择性全合成是通过使用改进的路线在 21 个步骤中完成的。有趣的 5,5-spiroketal-cis-fused-γ-lactone 核心是通过环氧化物的重排结合酸介导的 spiroketalization 构建的。