Aminium Salts Induced Desulphurization of Allyl and Diallyl Thiiranes. Synthesis of Dienes and Trienes
作者:Vincenzo Caló、Luigi Lopez、Angelo Nacci、Giuseppe Mele
DOI:10.1016/0040-4020(95)00502-y
日期:1995.8
conversion of methylene chloride in solutions of several allyl and diallyl episulphides 1–6 into the corresponding unsaturated derivatives 7–12. The desulphurization process, which occurs through a plausible chain electron-transfer mechanism, rapid and may proceed in a fashion that preserves the stereochemistry of the starting episulphide.
alpha-Ketosulphides of benzothiazole 1 react with allylic carbonates in the presence of palladium acetate in dichloromethane under mild conditions affording alpha,alpha-diallylated ketosulphides 2 in high yields. Reduction of 2 with sodium borohydride in isopropanol gives episulphides which in turn can be transformed almost quantitatively into trienes.