Corey-Gilman-Ganem

The Corey-Gilman ganem oxidation (also Corey-Ganem oxidation ), named after its discoverers EJ Corey , NW Gilman and BE Ganem, is a naming reaction from organic chemistry and was first published in 1968. The reaction describes the synthesis of esters from aldehydes or allylic alcohols .

An α,β-unsaturated aldehyde reacts to form an α,β-unsaturated methyl ester using manganese dioxide , potassium cyanide , and methanol .

Instead of the aldehyde, allyl alcohol can be used as starting material. Instead of methanol, another alcohol can be used for the esterification.

Example: Allyl alcohol reacts with the addition of manganese dioxide, potassium cyanide and ethanol to form ethyl acrylate :

The mechanism is described in the literature and is illustrated using the example of the overview reaction above:

In a nucleophilic attack caused by the cyanide ion at the carbon atom of the aldehyde 1 , this reacts to form a reactive ion 2 . Addition of manganese dioxide, consequent electron rearrangement and elimination of hydroxy(oxo)manganese gives intermediate 3 . Subsequent addition of the alcohol (here methanol) and subsequent release of hydrogen cyanide produces the ester (here the methyl ester 4 ).