The reaction of permanganate–periodate with 1-decene and 1-octadecene in aqueous suspension or media containing tert-butanol has been studied. C10-compounds are oxidized almost quantitatively with the aqueous reagent. Myrcene, cis-ocimene, citronellol, citronellal, citronellic acid, geraniol, nerol, linalool, and linalyl acetate are all oxidized in high yield to the predicted products. These can serve conveniently for chemical identification of the aliphatic terpenes when isolated from mixtures by gas–liquid chromatography. The reaction may also be useful in locating the 14C-label in tracer studies.