The oxidation of 1° and 2° alcohols to the corresponding aldehyde or ketone, using DMSO and oxalyl chloride is known as the Swern oxidation. First DMSO is activated by oxalyl chloride, releasing CO and CO2 gas to make a chlorosulfonium salt. The alcohol then attacks the chlorosulfonium salt and deprotonation by triethylamine (TEA) forms an alkoxysulfonium ylide. A proton transfer and rearrangement produces the final carbonyl compound and dimethyl sulfide.

  • Reagents: DMSO, Oxalyl Chloride, Solvent (DCM), Tertiary Amine (TEA, DIPA)
  • Reactant: 1° or 2° Alcohol
  • Product: Aldehyde or Ketone
  • Type of Reaction: Activated DMSO Oxidation
  • Bond Formation: C=O

Lab Tips

  • Care should be taken while running the reaction as DMSO reacts violently with oxalyl chloride in the absence of a solvent.
  • The chlorosulfonium salt is unstable above -60°C, so the oxidation is usually conducted at -78°C.
  • Steric hindrance of the substrate does not influence the efficiency of the oxidation.
  • Side reactions with oxalyl chloride are rare. If trifluoroacetic anhydride (TFAA) is used instead, side products are to be expected.
Kürti, L., Czakó, B. (2005). Strategic Applications of Named Reactions in Organic Synthesis; Background and Detailed Mechanisms. Burlington, MA: Elsevier Academic Press.


Top Citations

Original Paper

Related Reactions

Related Compounds

By shuhan yang


Just added to your wishlist:
My Wishlist
You've just added this product to the cart:
Go to cart page