TiCl₄‐Et₃N‐mediated condensation of ketones with methyl pyruvate afforded γ‐alkylidene butenolides via a tandem cross‐aldol addition/dehydroxylation/intramolecular lactonization process in one‐pot. The application of the methodology to the straightforward synthesis of elem‐1,3,7,8‐tetraen‐8,12‐olide, chloranthalactone A, and dehydromenthofurolactone, is demonstrated.

中文翻译：

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TiCl4-Et3N介导的一步法合成酮类γ-亚烷基丁烯内酯：在天然产物合成中的应用

TiCl ₄ - Et ₃ N介导的酮与丙酮酸甲酯的缩合反应通过一个锅中的串联交叉羟醛加成/脱羟基/分子内内酯化过程提供了γ-亚烷基丁烯内酯。演示了该方法在直接合成elem-1,3,7,8-tetraen-8,12-内酯，氯半乳糖苷A和脱氢薄荷脑内酯中的应用。