Highly E-selective solvent-free Horner–Wadsworth–Emmons reaction catalyzed by DBU
作者:Kaori Ando、Kyohei Yamada
DOI:10.1039/c1gc15134g
日期:——
The solvent-free Horner–Wadsworth–Emmons reaction of triethylphosphonoacetate with a variety of aldehydes was catalyzed by DBU in the presence of K2CO3 to give E-α,β-unsaturated esters highly selectively (99:1 for most of the reactions). The reaction with ketones gave trisubstituted olefins with good to high E-selectivity by DBU-Cs2CO3.
这 溶剂无Horner–Wadsworth–Emmons的反应 膦酸三乙酯 与各种 醛类DBU在K 2 CO 3的存在下催化得到E -α,β-不饱和酯类高度选择性(大多数反应为99 :1)。与之反应酮类 给出三取代 烯烃DBU-Cs 2 CO 3具有良好的电子选择性,甚至具有很高的电子选择性。
Biosynthesis of Terpenes. Preparation of (<i>E</i>)-1-Hydroxy-2-methyl-but-2-enyl 4-Diphosphate, an Intermediate of the Deoxyxylulose Phosphate Pathway
(E)-1-Hydroxy-2-methyl-but-2-enyl 4-diphosphate (E-6) was synthesized in six reaction steps from hydroxyacetone (9) and (ethoxycarbonylmethenyl)-triphenylphosphorane (11) with an overall yield of 38%. The compound was shown to be identical with the product of IspG protein, which serves as an intermediate in the nonmevalonate terpene biosynthetic pathway.
IspH Protein of the Deoxyxylulose Phosphate Pathway: Mechanistic Studies with C<sub>1</sub>-Deuterium-Labeled Substrate and Fluorinated Analogue
作者:Youli Xiao、Pinghua Liu
DOI:10.1002/anie.200803452
日期:2008.12.1
A facile synthetic method of α-quaternary-β,γ-unsaturated aldehydes via the stereoselective 1,4-elimination and α-regioselective Ferrier reaction
作者:Eiji Tayama、Ryo Hashimoto
DOI:10.1016/j.tetlet.2007.09.049
日期:2007.11
The 1,4-elimination reaction of 2-substituted-(2Z)-4-methoxy-O-alkenyl acetals with n-butyllithium is shown to afford the 2-substituted-(1Z,3E)-O-1,3-dienyl acetals in high stereoselectivities. The Ferrier reaction of the O-1,3-dienyl acetals thus obtained provides the corresponding alpha-quaternary-beta,gamma-unsaturated aldehydes in excellent yields with high alpha-regioselectivities. (c) 2007 Elsevier Ltd. All rights reserved.