A method for the deoxygenation of alcohols. The alcohol is first converted to the thiocarbonyl derivative, and is then treated with Bu3SnH. Once the radical chain has been initiated, attack on the Bu3Sn carrier by sulphur initiates a decomposition yielding the alkyl radical, for which Bu3SnH serves as hydrogen radical (H·) donor. The driving force for the reaction is the formation of the very stable S-Sn bonds.
Mechanism of the Barton-McCombie Reaction
The catalytic cycle, in which low concentration of .SnBu3 effects the reaction:
Radical-based transformation of vicinal diols to olefins via thioxocarbamate derivatives: a simple approach to 2',3'-didehydro-2',3'-dideoxynucleosides
M. Oba, M. Suyama, A. Shimamura, K. Nishiyama, Tetrahedron Lett., 2003, 44, 4027-4029.