Copper-catalysed regioselective S-alkylation and C-3(H)activation of 4-hydroxydithiocoumarin and 4-hydroxy-2H-chromene-2-thione: Easy access to 4-methyl-3,4-dihydrothiopyran derivatives†

An useful and expedient synthetic route for the synthesis of 4-methyl-3,4-dihydrothiopyran derivatives (3a-p & 6a-o) was accomplished from 4-hydroxydithiocoumarins/4-hydroxy-2H-chromene-2-thione and substituted vinyl ethers in the presence of 10 mol% Cu(I)...