Novel synthesis of 2-arylcyclohexanones using anodic oxidation of enol esters as the key step

A new route for the synthesis of 2-arylcyclohexanones starting from cyclohexanones was established. This synthetic route involves electrochemical oxidation as the key step and consists of the following four reaction steps: conversion of cyclohexanone (1) to the corresponding enol acetate (2), anodic oxidation in methanol providing 2-methoxycyclohexanone (3), Grignard reaction for introduction of an aryl group affording 1-aryl-2-methoxycyclohexanols (6) and acid-catalyzed treatment forming the 2-arylcyclohexanones (7). Thus, cyclohexanones bearing a variety of aryl groups at the α-position were prepared in good yields according to this newly developed method. This transformation starting from 1 to 7 may be characterized as a unique arylated 1,2-transposition of the carbonyl group.