Regioselective transformation of 6/5-fused bicyclic isoxazolidines to second-generation cyclic aldonitrones
作者:Basem A. Moosa、Shaikh A. Ali
DOI:10.3998/ark.5550190.0011.a12
日期:——
as face-selective. In solution, the 6/5 fused bicyclic cycloadducts remain solely as the cis-fused invertomers in order to accommodate the bulky tertiary substituent 2-hydroxy-2-propyl in the equatorial orientation. The cycloadducts, upon peracid oxidation, leads to the exclusive formation of synthetically important second-generation cyclic aldonitrones. The stereo- and face-selectivity of the cycloaddition
已发现 4-(2-羟基-2-丙基)-3,4,5,6-四氢吡啶 1-氧化物与单和二取代烯烃的环加成反应具有高度立体选择性和面选择性. 在溶液中,6/5 稠合双环环加合物仅作为顺式稠合的转化异构体保留,以便在赤道方向容纳庞大的叔取代基 2-羟基-2-丙基。环加合物在过酸氧化后导致合成重要的第二代环状醛硝酮的独家形成。这些第二代硝酮在 C(4) 和 C(6) 处带有取代基的环加成反应的立体选择性和表面选择性已经过简要检查。一个有趣的发现是处理第一代硝酮,即 4-(2-羟基-2-丙基)-3,4,5,6-四氢吡啶 1-氧化物,