Alcohol to Ketone

(Dess-Martin Periodinane)







Mechanism:



Dess-Martin periodinane mechanism - alcohol to ketone


Steps:

  1. The alcohol displaces an acetate from the Dess-Martin reagent.
  2. The proton on the now positively charged oxygen atom of the alcohol is picked up by an acetate molecule.
  3. Another molecule of acetate removes the proton attached to the carbon atom leading to the formation of the carbon oxygen double bond of the ketone. The process leads to a release of another acetate molecule and a mono-acetoxy iodinane.

Key Points:

  1. Two equivalents of acetic acid form during the rxn. If a substrate is sensitive to these mildly acidic conditions, then a base such as NaHCO3 or pyridine can be used to buffer the rxn.
  2. The mono-acetoxy iodinane by-pdt can be converted to easier to remove by-pdts during work-up by treatment with aq NaOH or Na2S2O3.