Conversion of aromatic ketones into α-arylalkanoic acids. Part 2. Routes employing peracid, chlorine, or nitrous acid

Abstract

Further methods for effecting the oxidative rearrangement of 1-arylalkanones to α-arylalkanoic esters have been investigated. It has been shown that appropriate α-iodoacetals, readily prepared from the ketones, can be converted into esters on treatment either with a peracid or with chlorine. Using the latter reagent, α-chlorination of the ester can be an unwanted side reaction with some substrates and the factors governing by-product formation are discussed. It is demonstrated that, employing chlorine, the process can be made catalytic in iodine. The acetals of 2-amino-1-arylalkanones have also been shown to give high yields of esters under diazotising conditions adding support to the suggestion that the ion, ArC(OR)₂CHR′, or an incipient version of the ion, is a key intermediate in the process.