An Efficient Flow-Photochemical Synthesis of 5<i>H</i>-Furanones Leads to an Understanding of Torquoselectivity in Cyclobutenone Rearrangements
作者:David C. Harrowven、Mubina Mohamed、Théo P. Gonçalves、Richard J. Whitby、David Bolien、Helen F. Sneddon
DOI:10.1002/anie.201200281
日期:2012.4.27
with the flow: 4‐Hydroxycyclobutenones were efficiently transformed into 5H‐furanones using an inexpensive flow‐photochemical setup. The results challenge the notion that this and the related thermochemical rearrangement display torquoselectivity in their electrocyclic opening to a vinylketene intermediate. Selectivity in the photochemical rearrangement is due a dichotomous reactivity of the (E)‐ and
顺应潮流:使用廉价的流光化学装置将4-羟基环丁烯酮有效地转化为5 H-呋喃酮。结果挑战了这样的观念,即这种反应和相关的热化学重排在其向乙烯酮中间体的电环开口中显示出对映选择性。光化学重排的选择性是由于(E)-和(Z)-乙烯基乙烯酮中间体的二分反应性(参见方案)。