carbonyl compounds in good yields by treatment with 1.5 equiv. of 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) in MeCN–H2O (9:1). The reactions of 2-aryl-substituted 1,3-dithianes bearing electron-donating groups on the benzene ring with DDQ afforded thioesters along with aldehydes. 1,3-Dithiolanes derived from aromatic aldehydes were transformed to thioesters, whereas 1,3-dithiolanes derived from aliphatic
Substitution Reaction of Ketene Dithioacetals with Carbon Electrophiles by the Promotion of Trityl Chloride-Tin(II) Chloride or Trimethylsilyl Chloride-Tin(II) Chloride Catalyst System
In the presence of catalytic amounts of trityl chloride or trimethylsilyl chloride and tin(II) chloride, ketene dithioacetals smoothly react with allyl methyl ethers or α,β-unsaturated orthoesters to afford the corresponding allyl or alkoxycarbonylethyl substituted ketene dithioacetals in good yields.