Alkenes chromium reagents, allylic

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. 

Chromium, trioxobisfpyridine)- Collins reagent, CrO)Py2, CrOy 2Py) allylic oxidation of alkenes, 116,120 oxn. of prim, alcohols, 125 oxn. of sec. alcohols (selective), 135 Chugaev pyrolysis of thioesters, 138,140-141 Cinchona alkaloids pr., 290... 

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