Abstract The aldoladdition of acyldiazomethane with aromatic aldehydes, vinyl aldehyde and aliphatic aldehydes was carried out efficiently in the presence of MgI2 etherate and iPr2EtN (DIPEA) using untreated reagent-grade CH2Cl2 under atmospheric conditions in good to excellent yields. Iodide counterion and a non-coordinating reaction media (i.e. CH2Cl2) are among the critical factors for the unique
Directaldolcondensation of various aromatic, heteroaromatic, α,β-unsaturated aldehydes and aliphatic aldehydes with acyldiazomethane was realized using MgI2 etherate (MgI2·(Et2O)n) as a promoter in the presence of diisopropyl amine (DIPEA) in excellent yields in a short time under mild conditions with high chemoselectivity. Iodide counterion, and a non-coordinating less ploar reaction media (i.e
Stereoselective Reduction of β-Hydroxy α-Ketoesters: A Concise Synthesis of<i>anti</i>-α,β-Dihydroxy Esters
作者:Jianbo Wang、Mingyi Liao、Wengang Yao
DOI:10.1055/s-2004-831210
日期:——
A new synthetic route to anti-α,β-dihydroxy esters has been developed. The new method consists of three steps starting from an aldehyde: the nucleophilic condensation with ethyl diazoacetate, oxidation with dimethyldioxirane, and stereoselective reduction with NaBH4.
DBU-catalyzed condensation of acyldiazomethanes to aldehydes in water and a new approach to ethyl β-hydroxy α-arylacrylates
作者:Fengping Xiao、Yu Liu、Jianbo Wang
DOI:10.1016/j.tetlet.2006.12.062
日期:2007.2
DBU-catalyzed condensation of ethyl diazoacetate (EDA) with aldehydes in pure water afforded corresponding beta-hydroxy alpha-diazo carbonyl compounds. The beta-hydroxy group of the products was further converted into beta-siloxy group. The Rh(II)-catalyzed reaction of the beta-aryl beta-siloxy alpha-diazo carbonyl compounds gave 1,2-aryl shift products predominantly. The three-step transformation constitutes an efficient synthesis of ethyl beta-hydroxy alpha-arylacrylates. (c) 2006 Elsevier Ltd. All rights reserved.
Zinc Derivative of Ethyl Diazoacetate in the Synthesis of α-Diazo-β-hydroxy Esters