Catalytic highly asymmetric 1,5(6)-selective cyclization reaction of α-hydroxyimino cyclic ketones: direct approach to ring-fused hydroxyimino dihydropyrans
作者:Luping Liu、Dekui Zhang、Panpan Zhang、Xianxing Jiang、Rui Wang
DOI:10.1039/c3ob41001c
日期:——
Herein, we have disclosed a catalytic asymmetric 1,5(6)-selective Michael/cyclization reaction of α-hydroxyimino cyclic ketones with γ,β-unsaturated α-keto esters. Unlike the previous catalytic strategies, this reaction provides a convenient 1,5(6)-selective asymmetric pathway to access synthetically useful ring-fused dihydropyrans. In general, high levels of yield, enantio- and diastereoselectivity (up to 99% yield, >99% ee and >20â:â1 dr) were obtained.
在此,我们公开了一种δ-羟基亚氨基环酮与δ,δ²-不饱和δ-酮酯的催化不对称 1,5(6)-选择性迈克尔/环化反应。与之前的催化策略不同,该反应提供了一种方便的 1,5(6)-选择性不对称途径,可获得合成上有用的环融二氢吡喃。总的来说,该反应获得了很高的收率、对映和非对映选择性(收率高达 99%,ee >99%,dr >20â:â1)。