Conversion of 5-(4',7'-Dimethyl-1',3'-dihydro-1',3'-ethano-2'H-inden-2'-ylidene)-2,2-dimethyl-1,3-dioxan-4,6-dione Into 3-Methylacenaphthylene in a Flash Vacuum Pyrolytic Experiment

Abstract

Flash vacuum pyrolysis of 5-(4′,7′-dimethyl-1′,3′-dihydro-1′,3′-ethano-2′ H-inden-2′-ylidene)-2,2-dimethyl-1,3-dioxan-4,6-dione (13) at temperatures in the range 600-750°p led to complex mixtures, but at higher temperatures (850°) it was converted into 3-methylacenaphthylene (major) and 1,4-dimethylnaphthalene (minor). 5-Ethenyl-1,4-dimethylnaphthalene on f.v.p. at 850° gave 5-methylacenaphthylene together with other compounds and was not on the reaction pathway.