Oxidations with Quinones

  Quinones bearing multiple electron withdrawing groups can function as hydride abstracting agents in situations where removal of hydride leaves a stabilized cation. Dicyanodichloroquinone (DDQ) is the most frequently used and most effective quinone for such applications.

  

Deprotection of PMB Ethers

  The most common use of DDQ in synthetic chemistry is the oxidative removal of p-methoxy benzyl groups, which allows the use of PMB as a protecting group orthogonal to almost all others.

Tedanolide Macrolactone: Hassfeld, J.; Eggert, U.; Kalesse, M. Synthesis 2005, 1183. DOI

  
  

Dehydrogenation of Ketones

  Although there are usually better reagents for this, DDQ and chloranil can be used to dehydrogenate ketones to enones.

Warburganal: Kende, A. S.; Blacklock, T. J. Tetrahedron Lett. 1980, 21, 3119

  

  Since these reactions proceed by hydride abstraction from the enol, prior conversion to enol silyl ether leads to more efficient reactions, with regiochemical control.. Carvone: Fleming, I.; Paterson, I. Synthesis 1979, 736