TREIBS Allylic oxidation

Examples of the use of chromium(VI) reagents to effect the allylic oxidation of alkenes to give a,3-unsaturated carbonyl compounds are very common in the literature. The reaction was first reported by Treibs and Schmidt for the allylic oxidations of a-pinene to verbenone and verbenol, of dipentene to carvone and caiveol, and of cyclohexene to cyclohexenol and cyclohexenone, using a solution of chromium trioxide in a mixture of acetic anhydride and carbon tetrachloride. However, yields were low and no synthetic use of this observation was made. 

Some other reactions involving oxidation of the C—Hg bond have been known for some time, but these are either of limited synthetic appeal or have experienced no significant development in recent years. Thus ozonolysis of the C—Hg bond to form carboxylic acids or ketones falls into the first category, whereas allylic acetoxylation of alkenes by Hg(OAc>2 falls into the second category. Nevertheless, this allylic oxidation (Treibe s reaction) has considerable synthetic utility, and has been reviewed quite recently.5 ... 

Vanadium(v) oxide and hydrogen peroxide are used in anhydrous tert-butyl alcohol, dilute methanol, or acetone solution. Experiments by Treibs and his collaborators135,136 showed that these reactions are unspecific since oxidation occurs at the allylic position as well as the desired hydroxylations. 

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