Direct synthesis of gamma-butyrolactones via gamma-phenyl substituted butyric acids mediated benzyl radical cyclization

Synthesis of several gamma -butyrolactones with aromatic substitution at carbon 5 from comparative gamma -aryl acids with 25-85% yield are covered. The straight oxidation in the presence of peroxydisulphate-copper(II)chloride system in aqueous medium was applied. The reaction is highly regioselective and leads exclusively to gamma -butyrolactone, through stable benzylic radical intermediate.