Spiro-compounds have been built up from methylcyclohexanone to examine, on the basis of the valency deflexion hypothesis, the nature of strain in cyclohexane ring in which ortho or meta positions are occupied by groups. β-Methylnaphthalene has been obtained as a product of dehydrogenation of 3-methylcyclohexane-spiro-cyclopmtane-­5'-carboxylic acid.