Studies Directed toward the Synthesis of the Unusual Antileukemic Diterpene Jatrophatrione. 1. A Solution to the Problem of Chirality Merger during Elaboration of the Entire Carbotricyclic Framework
作者:Leo A. Paquette、Shogo Nakatani、Thomas M. Zydowsky、Scott D. Edmondson、Li-Qiang Sun、Renato Skerlj
DOI:10.1021/jo9825254
日期:1999.4.1
tricyclic nucleus of jatrophatrione (1) is reported. The two key steps involve an oxyanionic Cope rearrangement and a Grob fragmentation. The building blocks required to reach 44 are the bicyclo[3.3.0]octanone 29 and the cyclopentadienyl bromide 35. The former was obtained in 12 steps from methylcyclopentadiene. The route to the latter began with 4,4-dimethylcyclopentenone. The charge-accelerated [3,3]-sigmatropic
据报道,有一种实用的途径可用于构筑麻风树三酮(1)的[5.9.5]三环核。这两个关键步骤涉及氧阴离子应付对重排和Grob碎片。达到44所需的结构单元是双环[3.3.0]辛酮29和环戊二烯基溴化物35。前者是由甲基环戊二烯分12步获得的。通往后者的途径始于4,4-二甲基环戊烯酮。烯醇化甲基化后,在44内的电荷加速[3,3]-σ异构化通过椅子状过渡态进行,以传递在中型环中带有反式双键的高度紧张的产物,其结果是快速的环状通过烯途径闭环。将该烯醇醚酸水解并转化为甲磺酸羟基酯51,然后暴露于碱。