THE MECHANISM OF HYDROGENOLYSIS AND ISOMERIZATION OF OXACYCLOALKANES ON METALS - 15 - TRANSFORMATION OF ETHYLOXIRANE AND VINYLOXIRANE ON CU-SIO2

The isomerization and hydrogenolysis of vinyloxirane and, for comparis on, those of ethyloxirane were studied on a Cu-SiO2, catalyst at 373 K in a recirculation reactor, at various hydrogen pressures and in the presence of deuterium. It was established that in the case of ethyloxi rane, the dominating reactions are deoxygenation associated with the f ormation of 1-butene and isomerization resulting in the formation of b utanal. In the case of vinyloxirane, the enlargement of the oxirane ri ng to a five-membered ring also takes place in addition to deoxygenati on and isomerization. Olefins are formed on Cu(0) while isomerization occurs on copper-copper oxide interfaces. The experimental results all ow the identification of the probable reaction pathways leading to the formation of the individual products. (C) 1998 Elsevier Science B.V. All rights reserved.