Corey‐Gilman‐Ganem Oxidation

Abstract The efficient synthesis of α,β‐unsaturated esters by treatment of α,β‐unsaturated aldehydes (or allyl alcohols) with manganese dioxide and potassium cyanide in a proper alcohol is known as Corey–Gilman–Ganem oxidation. The study finds that in presence of HCN and cyanide, the α,β‐unsaturated aldehydes convert into cyanohydrins, which are susceptible to the oxidation of MnO 2 to acyl cyanides and in presence of an alcohol, the α,β‐unsaturated esters are obtained. It has also been reported that this reaction works only for α,β‐unsaturated aldehydes and does not create any cis ‐ trans isomerization for the α,β‐unsaturated double bond. This reaction is unable to oxidize piperonal and allyl alcohols with extended conjugation and also has problem of the conjugate addition from cyanide ion.