Question

The chromate and manganate esters shown below form from the reaction of 3-butene-2-ol with chromic acid and manganese dioxide (MnO₂) respectively. They both decompose to give methyl vinyl ketone through mechanistically distinct pathways. (a) Provide the mechanism of the manganate ester decomposition and (b) indicate which intermediate in your mechanism rationalizes the observation that only allylic and benzylic alcohols react with MnO₂ to give carbonyl products.

10. [6 points) The chromate and manganate esters shown below form from the reaction of 3-butene-2-ol with chromic acid and manganese dioxide (MnO2) respectively. They both decompose to give methyl vinyl ketone through mechanistically distinct pathways. (a) Provide the mechanism of the manganate ester decomposition and (b) indicate which intermediate in your mechanism rationalizes the observation that only allylic and benzylic alcohols react with MnO2 to give carbonyl products. OH : Cr-OH methyl vinylketone chromate ester + Mn(OH)2 manganate ester methyl vinylketone

Answer 1

solution-10- H₂ Cr Oy On 애 mechanism. O=(r=0 +0-Mkou OOH w + HO - CV-OM co H Ст — ОН 04 Selective oxidation Mechanism a OH + O=Mn =0 _ + n H-0= Mno ОН omn-on Mn- oH MAOH + & allylic free radical Stublise by resonance