A peculiar transition-metal-free cyclodimerization of propargylic alcohols to vinyl bicyclic ketals

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• 作者：Boris A. Trofimov ; ^{boris_trofimov@irioch.irk.ru} ; Elena Yu. Schmidt ; Ivan A. Bidusenko ; Igor&rsquo ; A. Ushakov ; Nadezhda I. Protsuk ; Nadezhda V. Zorina ; Albina I. Mikhaleva
• 关键词：Acetylene ; Acetylenic alcohols ; 6 ; 8-Dioxabicyclo[3.2.1]octanes ; Super base
• 刊名：Tetrahedron
• 出版年：2012
• 出版时间：28 January, 2012
• 年：2012
• 卷：68
• 期：4
• 页码：1241-1246
• 全文大小：1171 K

文摘

Propargylic alcohols, alkylaryl(hetaryl)ethynyl carbinols, under transition-metal-free conditions (KOH/DMSO, 70-80?¡ãC, 10-15 min) unexpectedly undergo stereoselective cyclodimerization to 7-methylene-6,8-dioxabicyclo[3.2.1]octanes having the scaffold of known insect pheromones and marine toxins. Under acetylenic pressure the yields of bicyclic ketals reach 80 % . In all the cases, the cyclodimers are formed exclusively as one diastereomer.