Oxidative Enolate Cyclizations of 6,8-Nonadienoates: Towards the Synthesis of Prostanes
作者:Ullrich Jahn、Philip Hartmann、Ina Dix、Peter G. Jones
DOI:10.1002/1099-0690(200202)2002:4<718::aid-ejoc718>3.0.co;2-6
日期:2002.2
8-Nonadienoate enolates, which undergo radical 5-exo cyclization on SET oxidation with ferrocenium hexafluorophosphate, were studied as radical cyclization precursors. The trapping of the cyclized allylic radicals occurred with good regioselectivity through dimerization, TEMPO trapping, or SET oxidation/deprotonation reactions. 3-Alkoxido enolates were chemoselectively oxidized to β-oxy α-carbonyl radical anions
6,8-壬二烯酸烯醇化物在用六氟磷酸二铁鎓进行 SET 氧化时发生自由基 5-外环化,被研究为自由基环化前体。通过二聚化、TEMPO 捕获或 SET 氧化/去质子化反应,环化烯丙基自由基的捕获具有良好的区域选择性。3-烷氧基烯醇化物被化学选择性氧化为 β-氧 α-羰基阴离子,然后环化生成功能化的环戊烷衍生物。这些环化用作合成前列腺素和衍生物的模型研究。