Michael Additions versus Cycloaddition Condensations with Ethyl Nitroacetate and Electron-Deficient Olefins
作者:Elena Trogu、Francesco De Sarlo、Fabrizio Machetti
DOI:10.1002/chem.200802652
日期:2009.8.10
nitroacetate (1) reacts with electron‐poor olefins in the presence of a base to give either the Michael adducts 3 or the isoxazoline cycloadducts 4, resulting from water elimination. The proportions of the two products depend on the reaction conditions and change in the course of the process. Kinetic profiles for the two reactions show that the cycloaddition‐condensations require long induction times that dramatically
Ethyl 2-nitroacetoacetate as a new synthetic equivalent of ethoxycarbonylnitrile oxide
作者:V. P. Kislyi、A. L. Laikhter、B. I. Ugrak、V. V. Semenov
DOI:10.1007/bf00699144
日期:1994.1
It was shown that ethyl 2-nitroacetoacetate is a synthetic precursor of ethoxycarbonylnitrile oxide as well as of isoxazole- and isoxazoline-3-carboxylic acids and their esters. The elimination of acetic acid from ethyl 2-nitroacetoacetate occurs in a mixture of acetic acid and acetic anhydride in the presence of strong mineral acids, e.g., H2SO4, at room temperature and gives isoxazolines in yields of up to 85-91 %.
RIED, WALTER;FULDE, MARIA, CHEM.-ZTG., 113,(1989) N0, C. 315-319