Isolation of Dithiolanylium Salts and Their Conversion to Ketene Dithioacetals and Ortho Esters

Article abstract of DOI:10.1246/bcsj.59.453

Various 2-substituted 1,3-dithiolan-2-ylium perchlorates (1) were prepared by the reaction of 1,2-ethanedithiol with acyl chlorides in the presence of perchloric acid.Treatments of 1 with triethylamine gave 2-alkylidene-1,3-dithiolane (2) when the 2-substituent was a primary or secondary alkyl group. 2-Aryl derivatives of 1 were converted to ortho esters by the reaction with methanol in the presence of silver nitrate. 1,3-Dithian-2-ylium perchlorates and 2-alkylidene-1,3-dithianes were also prepared similarly from 1,3-propanedithiol.