412017-63-1Relevant articles and documents
Unusual tandem oxidative C-C bond cleavage and acetalization of chalcone epoxides in the presence of iodine in methanol
Jadhav, Balaso G.,Samant, Shriniwas D.
supporting information, p. 1591 - 1595 (2014/07/08)
An unusual reaction of chalcone epoxides is observed where chalcone epoxides on heating with iodine in methanol leads to α,α- dimethoxyacetophenones, through C-C bond cleavage followed by acetalization of the formyl group. The process occurs through ring
Solvent Microstructure Effect on Reaction Stereochemistry; Ring Opening of Chalcone Oxides
Durham, Dana,Kingsbury, Charles A.
, p. 923 - 930 (2007/10/02)
The stereochemistry and kinetics of acid-catalysed ring-opening reactions of epoxides are reported.Predominant inversion is found in the usual hydroxylic solvents.As the nucleophilicity of the solvent diminishes and acidity increases, the stereochemistry changes to predominant retention.Electron-donating substituents also tend to favour retention.In mixed solvents, the solvent microstructure is altered, leading to net retention for nucleophiles such as methanol.The exception is dioxane-methanol, which gives enhanced inversion.Molecular mechanics calculations indicate an electrostatic preference for the retention route, but a steric preference for inversion.The activation parameters indicate a negative entropy for both inversion and retention paths.Possible reasons are discussed for the entropy of the retention route being in the range normally found for A2 reactions.
