2-Alkenyl dioxolanylium cations, new reactive dienophiles in low temperature asymmetric Diels-Alder reactions
作者:Arnaud Haudrechy、Willy Picoul、Yves Langlois
DOI:10.1016/s0957-4166(96)00470-3
日期:1997.1
orthoesters 14–22 were prepared by an exchange reaction with orthoester 13. These compounds, after treatment with trimethylsilytriflate or tin(IV) chloride, gave rise to vinyl dioxolanylium cations which proved to be very reactive dienophiles in various Diels-Alder reactions.
Asymmetric Epoxidation of Aldehydes Catalyzed by New C2-Symmetrical Chiral Sulfide
作者:Miyuki Ishizaki、Osamu Hoshino
DOI:10.3987/com-02-9520
日期:——
Asymmetric synthesis of chiral epoxides from various aldehydes with benzyl bromide was investigated using new C-2-symmetrical chiral sulfides, which were readily prepared from (R,R)-tartaric acid.