Temperature- and Time-Dependent Stereochemical Control in Thermally Induced Keto−Ene Cyclizations
作者:Rafael Pedrosa、Celia Andrés、Carlos D. Rosón、Martina Vicente
DOI:10.1021/jo026525m
日期:2003.3.1
Reaction conditions determine the stereoselection in the intramolecular keto-ene reaction. The thermolysis of chiral 2-acyl-3-allyl-substituted 1,3-perhydrobenzoxazines derived from (-)-8-aminomenthol gives a mixture of only two cis-3-hydroxy-3,4-disubstituted pyrrolidine nuclei. The stereochemistry of the major diastereoisomer depends on both the temperature and the reaction time.
反应条件决定了分子内酮-烯反应中的立体选择。衍生自(-)-8-氨基薄荷醇的手性2-酰基-3-烯丙基取代的1,3-过氢苯并恶嗪仅热解两个顺式-3-羟基-3,4-二取代的吡咯烷核的混合物。主要的非对映异构体的立体化学取决于温度和反应时间。