The Reaction of 1-Amino-2,3-diphenylcyclopropenium Ions with 1,3-Diketones to Afford 2,4-Cyclopentadien-1-ols: The Regioselective Ring-Opening of 1-Aminocyclopropene Intermediates
作者:Hiroshi Yoshida、Tomoji Tamai、Tsuyoshi Ogata、Kiyoshi Matsumoto
DOI:10.1246/bcsj.61.2891
日期:1988.8
1-Amino-2,3-diphenylcyclopropenium tetrafluoroborates (4) reacted with cyclic or acyclic 1,3-dicarbonyl derivatives (5) such as 1,3-diketones, β-keto esters, or gem-diesters in the presence of triethylamine to give 2,4-cyclopentadien-1-ols in moderate to good yields. Some isolated cyclopropene intermediates were, upon heating, converted to the corresponding cyclopentadienols. The factors that influence on the reactivities of 4 and 5 (basicities of the amino groups of 4 and bulkiness of the substituents of 4 and 5) are discussed qualitatively.
1-氨基-2,3-二苯基环丙基四氟硼酸盐(4)与环状或非环状1,3-二羰基衍生物(5)如1,3-二酮、β-酮酯或gem-二酯在存在三乙胺的情况下反应,以中等至良好的产率生成2,4-环戊二烯-1-醇。一些分离的环丙烯中间体在加热后转化为相应的环戊二烯醇。定性讨论了影响4和5反应活性的因素(4中氨基的碱性和4和5中取代基的体积)。