Remote Asymmetric Induction in Lewis Acid-Catalyzed Diels-Alder Reaction of .ALPHA.,.BETA.-Unsaturated Enones Having a Chiral Sulfinyl-Substituted, 5-Membered Aromatic Heterocycle.
Remote Asymmetric Induction in Lewis Acid-Catalyzed Diels-Alder Reaction of .ALPHA.,.BETA.-Unsaturated Enones Having a Chiral Sulfinyl-Substituted, 5-Membered Aromatic Heterocycle.
A highly asymmetric, Lewis acid-catalysed Diels–Alder reaction using optically active 2-(3-tolyl p-sulfinyl)furyl α,β-unsaturated ketones as a dienophile
The Diels-Alder reaction of chiral 2-(3-tolyl-p-sulfinyl)furyl alpha,beta-unsaturated ketones 3 and 4 with cyclopentadiene in the presence of a Lewis acid proceeds smoothly to give the corresponding endo adducts 5a and 6a, respectively, in excellent yield with high diastereoselectivity.
Remote Asymmetric Induction in Lewis Acid-Catalyzed Diels-Alder Reaction of .ALPHA.,.BETA.-Unsaturated Enones Having a Chiral Sulfinyl-Substituted, 5-Membered Aromatic Heterocycle.
作者:Yoshitsugu ARAI、Tsutomu MASUDA、Yukio MASAKI
DOI:10.1248/cpb.46.1078
日期:——
Two types of chiral sulfoxides as Diels-Alder dienophiles were synthesized and high levels of diastereoselectivity were observed in cycloadditions. 2-Furyl and 2-thienyl α, β-enones, bearing a chiral sulfinyl group in the heterocycle, served as efficient dienophiles in Diels-Alder reactions, where the catalytic use of aluminium chloride or a lanthanide triflate effected the cycloaddition with cyclopentadiene affording the endo adduct with high diastereoselectivity, ranging from 91% to 98%.