Hydrogenation and Hydrogenolysis. XII. The Hydrogenation of Isomeric Dimethoxybenzenes with Platinum Metal Catalysts

Abstract The catalytic hydrogenation and hydrogenolysis of isomeric dimethoxybenzenes over six platinum metals have been investigated at elevated temperature and pressure. The hydrogenolysis of methoxyl group occurred more extensively over Group VIII3 metals than over Group VIII2metals. The meta isomer hydrogenolyzed to greater extent and gave smaller cis/trans ratio of dimethoxycyclohexane, than the ortho and para isomers. The greater tendency of the meta isomer toward hydrogenolysis supports the previously proposed explanation according to which the electron-releasing group at meta position would promote hydrogenolysis.