A Route to 5,5-Dithiospiroketals and to Long-Chain Monomers fromthe Biomass

5,5-Dithiospiroketals are prepared by a double radicaladdition of alpha,alpha '-bisxanthyl acetone to an alkene followed by ionic orthermal cleavage of the xanthate groups and acid-catalyzed ring closure.A modification employs alpha-chloro-alpha '-xanthyl acetone to give unsym-metrical derivatives. Reductive removal of the sulfur atoms with Raneynickel furnishes long-chain alpha,omega-diacids, diols, and diamines. Usingbiosourced alkenes, monomers and polymers can be obtained whereessentially all the carbons are derived from the biomass.

Automated summary

This article describes the preparation of 5,5-dithiospiroketals through a double radical addition and ring closure reaction, as well as the process of obtaining long-chain compounds by reductive removal of sulfur atoms. In addition, the method of using biosourced alkenes to prepare monomers and polymers is also discussed.