On the Oxidation of Guaiazulene

Abstract Guaiazulene was oxidized with potassium permanganate and with selenium dioxide according to the Treibs procedure. An acidic and a neutral crystalline compounds obtained from the permanganate oxidation in acetone were identified by means of UV, IR, and NMR spectrum measurements as 4-methyl-7-isopropylazulene-1-carboxylic acid and 1-formyl-4-methyl-7-isopropylazulene respectively. It was also confirmed that the selenium dioxide oxidation of guaiazulene in acetone gave 3-formylguaiazulene and 3,3′-diguaiazulenylacetone, the chemical structure of which had already been established by Treibs.