Periodate Oxidation of Phenols. IX. Oxidation of o-(omega-Hydroxyalkyl)phenols.

Abstract

The oxidation of salicyl alcohol with sodium metaperiodate in aqueous solution was found to result in the formation of spiroepoxy-2,4-cyclohexadienone 5, which, however, could not be isolated, since it dimerised rapidly by Diels-Alder reaction to give compound 7. Analogous dimers were obtained from the 3,5-dimethyl, the 3-hydroxymethyl-5-methyl, and the 3-methoxy derivatives of salicyl alcohol, one of several possible dimers only being observed in each case. Periodate oxidation of two homologs of salicyl alcohol was also examined. 2-(2-Hydroxyphenyl)ethanol gave the same dimeric spirooxirane as had been obtained from salicyl alcohol, one mol of formaldehyde per mol of starting material being liberated. The next homolog, 3-(2-hydroxyphenyl)propanol, reacted in the normal way, to give the dimeric spirooxolane.