TiCl₄−Et₃N or −Bu₃N reagent conducted a highly (Z)‐stereoselective carbon homologation (dehydration type Ti‐Claisen condensation) of alkyl α‐heteroatom (halo and sulfonyloxy)‐substituted acetates (XCH₂CO₂R) with alkyl formates (HCO₂R) to afford various alkyl β‐alkoxy‐α‐halo or sulfonyloxy‐substituted acrylates (24 examples; 51%–91% yield). Stereoretentive Suzuki‐Miyaura, Negishi, and Sonogashira cross‐couplings using the obtained methyl β‐methoxy‐α‐halo or sulfonyloxy‐substituted acrylates proceeded smoothly to produce a variety of β‐alkoxy‐α‐substituted acrylates in moderate to high yield (35 examples; 29%–99% yield). As a successful application, a 3‐step straightforward synthesis of strobilurin A was performed utilizing the present reaction sequence (dehydration type Ti‐Claisen condensation and Suzuki‐Miyaura cross‐coupling), wherein the geometry of the three consecutive olefins (2E,3Z,5E) was completely maintained.

中文翻译：

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烷基形式的α-杂原子取代的乙酸酯的脱水Ti-Claisen缩合（碳同位）：作为（Z）-立体定义的交叉偶联伙伴的用途及其在Strobilurin A的简明合成中的应用

的TiCl ₄ -Et ₃ Ñ或-Bu ₃ ñ试剂进行的高度（ż烷基α-杂原子（卤和磺酰氧基）的）-stereoselective碳同系化（脱水型Ti克莱森缩合）取代的乙酸盐（XCH ₂ CO ₂ R）与烷基甲酸酯（HCO ₂ R）生成各种烷基β-烷氧基-α-卤代或磺酰氧基取代的丙烯酸酯（24例；收率51％–91％）。使用获得的甲基β-甲氧基-α-卤代或磺酰氧基取代的丙烯酸酯的立体定向Suzuki-Miyaura，Negishi和Sonogashira交叉偶联反应顺利进行，以中等至高收率生产了多种β-烷氧基-α-取代的丙烯酸酯（35例子； 29％–99％的收益）。作为一项成功的应用，利用现有的反应顺序（脱水型Ti-Claisen缩合和Suzuki-Miyaura交叉偶合）进行了三步法直接合成的strobilururin A，其中三个连续烯烃的几何构型（2 E，3 Z，5 E）被完全维持。