Organic synthesis with α-chloro sulphides. Preparation of aromatic γ-lactones from phenols and α-chloro sulphide carboxylates

Lewis acid-catalysed alkylation of para-substituted phenols using α-chloro sulphides as electrophiles yields sulphenylated γ-lactones which can be desulphurised with zinc in acetic acid or Raney nickel. This synthesis has been applied to p-cresol, 2-naphthol, and two phenolic dihydrocinnamates. Alkylation of 1,4-dimethoxybenzene yields homogentisic acid dimethyl ether after desulphurisation and hydrolysis.