Selenium Dioxide

Selenium Dioxide

Overall Score4
  • Generality
  • Reagent Availability
  • Experimental User Friendliness
  • General Characteristics

Selenium dioxide oxidizes allylic C-H bonds, providing an option to synthesize allylic alcohols from alkenes. Even though SeO2 is a toxic reagent, it is used frequently since it mediates a transformation that is hard to effect by other means. The reaction conditions are mild too.

When re-oxidants such as TBHP (tert-butyl hydroperoxide) are used, SeO2 can be reduced to substoichiometric amounts.

  • General References

  • Riley, H. L.; Morley, J. F.; Friend, N. A .C. J. Chem. Soc. 1932, 1875.
  • Rabjohn, N. Org. React. 1949, 5, 331.
  • Rabjohn, N. Org. React. 1976, 24, 261.
  • Bulman Page, P. C.; McCarthy, T. J. Comprehensive Organic Synthesis 1991,7, 84, 108.


  • Reaction Mechanism

The reaction mechanism is generally explained by the ene reaction followed by [2,3]-sigmatropic rearrangement. (Ref: J. Org. Chem. 200065, 7554., Tetrahedron Lett. 200344, 1099.)


  • Examples

The total synthesis of vinblastine.[1]


The total synthesis of resiniferatoxin.[2]


The total synthesis of tetrodotoxin[3]: Under the conditions using PhSeSePh/PhIO2/Py (the Barton modification),[4] the substrates are oxidized all the way to enones.


The α-position of carbonyl compounds is also susceptible to oxidation by SeO2. Various oxidation products can be synthesized depending on the conditions.


  • Experimental Procedure

Allylic oxidation of geranyl sulfone.[5]


  • Experimental Tips

  • References

[1] Fukuyama,T. et al. J. Am. Chem. Soc. 2002124, 2137. DOI: 10.1021/ja0177049 [2] Wender, P. A. et al. J. Am. Chem. Soc. 1997119, 12976. DOI: 10.1021/ja972279y [3] Hinman, A.; Du Bois, J. J. Am. Chem. Soc. 2003125, 11510. DOI: 10.1021/ja0368305 [4] Barton, D. H. R.; Crich, D. Tetrahedron 198541, 4395. doi:10.1016/S0040-4020(01)97207-2 [5] Marshall, J. A.; Andrews, R. C. J. Org. Chem. 198550, 1602. DOI: 10.1021/jo00210a009

  • Related Reactions


  • Related Books

  • External Links

, , ,