Studies on Chiral Organosulfur Compounds. III. Lewis Acid-Catalyzed Intramolecular Asymmetric Pericyclic Reactions of Chiral .ALPHA.-Acetyl and Methoxycarbonylvinylic Sulfoxides.
作者:Kunio HIROI、Masayuki UMEMURA、Aki FUJISAWA
DOI:10.1248/cpb.41.666
日期:——
A chiral α-sulfinyl α, β-unsaturated ketone served as a good chiral diene or enophile in intramolecular Lewis acid-catalyzed asymmetric pericyclic reactions, giving hetero-Diels-Alder reaction products, together with ene reaction products in some cases, in high optical yields. The reaction pathways for Diels-Alder or ene reactions were readily controlled depending on the Lewis acids used. A chiral α-sulfinyl α, β-unsaturated ester served as a good enophile to give ene reaction products with high enantioselectivity. The mechanistic pathway for the asymmetric induction is proposed on the basis of the stereochemical results obtained.
一种手性的α-亚磺酰基α,β-不饱和酮在分子内路易斯酸催化的不对称周环反应中作为良好的手性二烯或亲烯,生成异源的Diels-Alder反应产物,以及在某些情况下的烯反应产物,且具有高光学产率。Diels-Alder或烯反应的反应途径可以根据所使用的路易斯酸进行有效控制。一种手性的α-亚磺酰基α,β-不饱和酯作为良好的亲烯,生成具有高对映选择性的烯反应产物。基于获得的立体化学结果,提出了不对称诱导的机制路径。