STRAINLESS MONOCYCLIC RINGS. PART III. SYNTHESIS OF 2-METHYL-CYCLOHEXANESUCCINIC ACID AND THE SEPARATION OF ITS ISOMERS.

2-Methylcyrlohexane-r-carboxy-I-acetic acid, on being carefully separated, gives four isomeric modifications, melting respectively at 162°, 155°, 153° and 142°. The individua­lity of the acids has been proved by a study of the properties of their anilic acids, as well as the imides. Of the four acids, two are capable of undergoing change into the other two, through their anhydrides. The same phenomenon has also been observed in the case of the m-methylcyclohexane-succinic acids described in a previous communication. The work as now complete, leaves no doubt as to the validity of the hypothesis of release of strain in cyclahezane ring, under certain conditions.