Methylcyclohexenes are formed by the partial hydrogenation of toluene to methylcyclohexane over ruthenium catalyst.

[2] 1-Methylcyclohexene is used as a probe of the stereochemistry of reactions involving alkenes because it is prochiral and the two sp2-carbon atoms differ.

The poor selectivity is due to the migration of the double bond in the cyclohexene ring.

All these products can be further reacted with Grignard reagents such as ethynylmagnesium bromide to synthesize ethynyl derivatives.

The main product has the formyl group on the less substituted alkene-carbon, trans with respect to the methyl substituent.