Diastereofacial selectivity in Diels-Alder reactions of chiral 2-substituted-1,3-dienes.
作者:Robert Bloch、Nathalie Chaptal-Gradoz
DOI:10.1016/s0040-4039(00)60028-x
日期:1992.10
described. Thermal Diels-Alder reactions between these dienols or their ethers 3 and various dienophiles give rise with fair to good regio- and diastereoselectivity to monocyclic “para” adducts. In contrast a total regioselectivity and an excellent π-facial selectivity is observed when the Diels-Alder cycloadditions of the dienic ethers 3 are conducted in the presence of a Lewis acid.
从氯丁二烯开始,描述了烷基和芳基(1,3-丁二烯-2-基)甲醇1的改进的合成。这些二烯醇或它们的醚3与各种亲二烯体之间的热Diels-Alder反应产生了对单环“对”加合物的公平至良好的区域和非对映选择性。相反,当在路易斯酸的存在下进行二烯醚3的狄尔斯-阿尔德环加成反应时,观察到总区域选择性和优异的π表面选择性。