CONDENSATION D'ALCENES AROMATIQUES AVEC L'ACETALDEHYDE CATALYSEE PAR DES RESINES ECHANGEUSES D'IONS-II; STEREOISOMERISATION ET SYNTHESE DE NOUVEAUX DIOXA-1,3 CYCLOHEXANES POLYSUBSTITUES

Article abstract of DOI:10.1016/S0040-4020(01)92157-X

The interconversion of the three stereoisomers of 4-anisyl-2,5,6 trimethyl-1,3 dioxacyclohexane, obtained from the condensation reaction between anethole and acetaldehyde, depends on the experimental conditions.In some cases, a reversal to the starting alkene could be observed: such a phenomenon does not seem to have been reported so far in the isomerization reactions of 1,3-dioxacyclohexanes.The data can be accounted for by a reaction mechanism involving various cationic intermediates.New 1,3-dioxacyclohexanes were obtained from acetaldehyde and various aromatic alkenes under mild reaction conditions in the presence of sulfonic ion-ex changers used as catalysts, in good yields and with high selectivity.