The pyrolysis of polycarbonyl compounds. IV. Pyrolysis of 3,3-dimethylindane-1,2-dione and o-isopropenylbenzaldehyde at 600° and 800°

Abstract

Pyrolysis of 3,3-dimethylindane-1,2-dione (IV) at 600°/0.6 mm with short contact time gave benzofulvene (V), o-isopropenylbenzaldehyde (VI), and 3-methyl-indan-1-one (VII). The aldehyde (VI) was shown by deuterium labelling to undergo randomization of hydrogen atoms between the aldehyde and isopropenyl groups at 600°. Pyrolysis of the dione (IV) at 800°/0.6 mm gave the hydrocarbons phenyl-acetylene, styrene, α- methylstyrene, o-methylstyrene, indene, benzofulvene, and naphthalene; the formation of these from the products (VI) and (VII) is discussed.