Reactions de cycloaddition dipolaire-1,3 des thiazolones mesoioniques avec des composes ethyleniques-1
作者:M. Baudy、A. Robert、G. Guimon
DOI:10.1016/0040-4020(82)85110-7
日期:1982.1
The stereochemistry of cycladducts obtained through the reaction of mesoionic thiazolones with ethylenic dipolarophiles is established. The dipole-dipolarophile approach is discussed in terms of interactions between the frontier orbitals. When the dipolarophile is acrylonitrile we note the importance of the destabilising interaction the HOMO orbitals. When the dipolarophile is vinyl ethyl ether we
Reaction de Cycloaddition dipolaire-1,3-des thiazolones et des selenazolones mesoioniques avec l'acetylene dicarboxylate de methyle—II
作者:M. Baudy、A. Robert、C. Guimon
DOI:10.1016/0040-4020(82)85160-0
日期:1982.1
Mesoionic thiazolones and selenazolones react with dimethyl acetylene dicarboxylate to give thiophenes or pyridones. We show that the reactivity of the mesoionic thiazolones towards dimethyl acetylene dicarboxylate may be explained by second order perturbation theory, limited to frontier orbitals. The influence of the temperature and of the nature of the substituants on the evolution of the primary
The relative configuration of the carbons bearing the ester groups in the cycloadducts of anhydro - 4- hydroxythiazolium hydroxides with dimethylmaleate and dimethylfumarate is revised in the light of an X-ray crystallographic analysis. Steric effects are considered to account for the preferred exo approach of the dipole and the dipoiarophile.