Propensity of 4-Methoxy-4-vinyl-2-cyclopentenones Housed in Tri- and Tetracyclic Frameworks for Deep-Seated Photochemical Rearrangement
作者:Leo A. Paquette、Fabrice Gallou、Zhong Zhao、David G. Young、Jian Liu、Jiong Yang、Dirk Friedrich
DOI:10.1021/ja001813q
日期:2000.10.1
tetracyclic 2-cyclopentenones has been examined in two solvents. Prepared by a convergent pathway involving the coupling of cyclopentenyl bromide 12 to several chiral ketones followed by desilylation, perruthenate oxidation, and ring-closing metathesis, the reactants were conveniently irradiated through quartz. Following promotion to the triplet level, a cyclopropylcarbinyl biradical intermediate is presumably
已在两种溶剂中检查了一组选定的高度对映体富集的三环和四环 2-环戊烯酮的激发态行为。通过涉及环戊烯基溴 12 与几个手性酮偶联,然后进行脱甲硅烷基化、高钌酸氧化和闭环复分解反应的收敛途径制备,反应物可以方便地通过石英照射。升级到三重态后,如果连接到 C4 的双键未饱和,则可能会生成环丙基羰基双自由基中间体。已观察到四种途径起作用,之前在相当不同的条件下仅观察到其中一种。新的光重排包括非诺里分裂成乙烯酮,产生螺环中间体,在四元环的分子内断裂之前,环扩展为环丁基。在后一种情况下,形成氢化茚酮衍生物。在大多数示例中,公...