Electron impact studies of 4a-Methyl-4,4a-dihydrophenanthren-2(3H)-one and related phenanthrones

Abstract

The mass spectra of 4a-methyl-4,4a-dihydrophenanthren-2(3H)-one and closely related phenanthrenones have been studied. The suggested fragmentation processes, substantiated by high-resolution mass measurements and appropriate metastable peaks, are shown to be characteristic of compounds with the same hydro-oxo-phenanthrene chromophore. 2-Cinnamylidene-6-methyl-cyclohexanone possessing a similar chromophore is also shown to exhibit a comparable fragmentation pattern.