stereogenic centers of the obtained products were constructed with high diastereo- and enantioselectivity (up to >99% de and 92% ee). The reaction was successfully applied to the asymmetric synthesis of (−)-epibatidine, which was synthesized from the cyclohexanone derivative in seven steps in 30% overall yield.
Bifunctional thiourea-catalyzed enantioselective double Michael reaction of γ,δ-unsaturated β-ketoester to nitroalkene: asymmetric synthesis of (−)-epibatidine
作者:Yasutaka Hoashi、Takaya Yabuta、Yoshiji Takemoto
DOI:10.1016/j.tetlet.2004.10.082
日期:2004.12
The asymmetric synthesis of 4-nitrocyclohexanone derivatives has been accomplished by enantioselective double Michael additions of γ,δ-unsaturated β-ketoesters to nitroalkenes using a catalytic amount of bifunctional thiourea and TMG. The three contiguous stereogenic centers of the obtained products were constructed with good to high diastereoselectivity and up to 92% ee. The biologically active natural
A highly stereoselectivesynthesis of terminally substitutedethyl 3-oxo-4-pentenoates 3 from γ-phosphorylated ethylacetoacetate 2 and diverse carbonyl compounds was accomplished.
Anionic activation of stabilized ylides. A highly Z-stereoselective wittig reaction of (3-ethoxycarbonyl-2-oxopropylidene)triphenyl-phosphorane with aliphatic aldehydes
作者:K. Michał Pietrusiewicz、Jarosław Monkiewicz
DOI:10.1016/s0040-4039(00)84088-5
日期:1986.1
BODALSKI R.; PIETRUSIEWICZ K. M.; MONKIEWICZ K. M.; KOSZUK J., TETRAHEDRON LETT., 1980, 21, NO 23, 2287-2290
作者:BODALSKI R.、 PIETRUSIEWICZ K. M.、 MONKIEWICZ K. M.、 KOSZUK J.