The first, total synthesis of (+)-brasilenyne (1) has been achieved in 19 steps from l-(S)-malic acid. The key elements of this approach are a highly diastereoselective ring-opening of a 1,3-dioxolanone with bis(trimethylsilyl)acetylene) promoted by TiCl4 to set a propargylic stereocenter and the successful application of the sequential ring closing metathesis/silicon-assisted intramolecular cross-coupling
首先,(+)-brasilenyne (1) 的全合成是在 19 个步骤中从 l-(S)-
苹果酸实现的。这种方法的关键要素是由 TiCl4 促进的
1,3-二氧戊环酮与双(三
甲基甲
硅烷基)
乙炔的高度非对映选择性开环以设置炔丙基立体中心以及顺序闭环复分解/
硅辅助分子内的成功应用用于构建 1 的 oxonin 核心结构的交叉偶联反应。