Structure of the Products of the Cyclooligomerization of Sulfur Dioxide with Diethyl Diallylmalonate

Abstract

The AIBN-initiated cooligomerization of sulfur dioxide with diethyl diallylmalonate in the presence of bromotrichloromethane or thiophenol was investigated. ES/MS and NMR studies show that 1:1 cooligomers of cis-linked 5-membered rings are formed. Electrospray mass spectrometry demonstrates that, in the case of CCl3Br, the end group is −CH2Br, and 13C NMR demonstrates that the other end group is −Cl2CCl3. The thiophenol reaction leads to end groups of either −CH3 or −CH2SO2H with PhSCH2 at the other end. The molecular weight of oligomers was inversely proportional to the concentration of the chain-transfer agent. The polymerization chain transfer constants for bromotrichloromethane and thiophenol are 4.63 × 10-4 and 8.10 × 10-4, respectively, at 81 °C.