Essential oils and their constituents. XLII. Isomerization of epoxides on active alumina

When chromatographed on active alumina, epoxides isomerize yielding chiefly the corresponding α,β-unsaturated alcohols. Side reactions were observed in some cases. Limonene oxide yielded cis-1 (7), 8 p-menthadien-ol-2, cis- and trans-carveol, perillyl alcohol, trans-8p-menthene-diol-1,2, and cis- and trans-dihydrocarvone. α-Pinene oxide was converted to pinocarveol, cis- and trans-pinocamphone, campholenic aldehyde and an unidentified alcohol. Caryophyllene oxide yielded three isomeric unsaturated alcohols which were converted to a ketone of known structure.