Definition and Introduction:-
Cis-diols is formed in this reaction.This reaction is mainly proceed in the presence of iodine and silver acetate reagant.
Woodward reaction after the opposite facial selectivity as compared to oxidation with OSO4.Steroid intermediate here the steroic approach factor first direct the stereochemistry of the iodination,which is followed by7 hydroxylation from opposite face.Where as OSO4 leads to the isomeric Cu-diols by direct attack from the most accessible face.
General Reaction:-
Mechanism :-
- First Step mean the addition of iodine deads to a cyclic iodinium ion that is opened through a nucloeophilic subsitution by acetate ions.
- Second step mean the deored product can be isolated after hydrolysis.
- See the picture of the mechanism
More Greener reaction is Woodward or Upjohn ?
- Upjohn uses highly toxic and volatile OSO4 in the reaction but is used only.
- Woodward hydroxylation utilizes metal in stiochmetric amount along with halogen which is used stochiometric only
