
%0 Journal Article
%A Andersonmckay, JE 
%A Liepa, AJ 
%T The Synthesis of 4-Hydroxydithiocoumarins: A Case of Unusual Tautomer Stability
%J Australian Journal of Chemistry
%D 1987/07/01
%V 40
%N 7
%P 1179-1190
%K 
%R https://doi.org/10.1071/CH9871179
%U https://www.publish.csiro.au/paper/CH9871179 
%X 2'-Chloroacetophenones react with carbon disulfide in the presence of sodium hydride to form 4-hydroxydithiocoumarin anions. Kinetic protonation provides the 4-hydroxydithiocoumarins which can be tautomerized to 2-mercapto-1-thiochromones by treatment with strong acid.   Both tautomers are quite stable and do not readily interconvert. Alkylation of either 4-hydroxydithiocoumarin or 2-mercapto-1-thiochromone provides S-alkyl derivatives exclusively while acylation with acid anhydrides gives mixtures of O- and S-acyl products. Oxidation with sodium perborate yields the exocyclic monosulfoxide while m-chloroperbenzoic acid gives the exocyclic sulfone. 
