Convenient synthesis of substituted cyclopentenones via [3 + 2] annulation of allylidenetriphenylphosphorane with 1,2-diacylethylenes: application to synthesis of (±)-methyl dehydrojasmonate
作者:Yuichiro Himeda、Yasuhiro Tanaka、Ikuo Ueda、Minoru Hatanaka
DOI:10.1039/a709296b
日期:——
(3-Alkoxycarbonyl-2-ethoxyprop-2-enylidene)triphenylphosphoranes 1 and 2 undergo [3 + 2] annulation with 1,2-diacylethylenes 3 to give 2-ethoxycyclopentadienes 6 as mixtures of the 1,3- and 1,4-diene. The mixtures are conveniently converted upon mild acid treatment into cyclopentenones 7 in a single form. Annulation of phosphorane 1 with acylmethylenemalonates 10 affords cyclopenta-1,3-dienes 11 in
(3-烷氧基羰基-2-乙氧基丙-2-烯基)三苯基膦酸酯与1,2-二丙烯基乙烯3进行[3 + 2]环化反应,得到2-乙氧基环戊二烯6,为1,3-和1,4-的混合物二烯。混合物经温和酸处理后方便地转化为单一形式的环戊烯酮7。膦烷1与酰基亚甲基丙二酸酯10的环化以高度区域选择性的方式提供环戊-1,3-二烯11,其易于以优异的产率转化为取代的环戊烯12。磷烷1也用1,2-酰基乙炔14进行环化,得到富叶烯15,其转变成外亚甲基环戊烯酮16。此外,描述了环化在(±)-甲基脱氢茉莉酮酸酯的合成中的应用。