Oxidation of benzylic and allylic alcohols with chemical manganese dioxide smoothly proceeded under mild reaction conditions to give the corresponding aldehydes and ketones, respectively, in high yields. It is well-known that activated manganese dioxide (MnO2) is a useful reagent both for selective oxidation of benzylic and allylic alcohols to aldehydes and ketones, respectively, and for dehydrogenation of heterocycles to heteroaromatics. 1 Although several methods for preparation of activated MnO2 have been reported, 2 preparations are very tedious and sometimes the oxidation efficiency lacks reproducibility. Commercially available activated MnO 2 can also be used, but again its activity varies widely. We have already reported that chemical manganese dioxide (CMD), 3 produced for dry battery manufacture, can be efficiently used for oxidation of some allylic alcohols 4 and for dehydrogenation of heterocycles such as thiazolines, 5 2,3- dihydrofurans, 6 3-pyrrolines, 7 and 2-pyrrolines. 8 Further investigations along this line have revealed that CMD is widely applicable to the selective oxidation of benzylic and allylic alcohols 1 to aldehydes and ketones 2, respectively, as shown in Scheme 1.