Kornblum oxidation

[1][2][3] Similar to sulfonium-based oxidation of alcohols to aldehydes reactions, the Kornblum oxidation creates an alkoxysulphonium ion, which, in the presence of a base, such as triethylamine (Et3N), undergoes an elimination reaction to form the aldehyde or ketone.

However, using an additive such as silver tetrafluoroborate allows the reaction to work on a wider range of substrates, as often seen for alkyl-halide substitutions, or they can be converted first to the corresponding alkyl tosylate.

[4][5] The reaction was initially limited to activated substrates, such as benzylic and α-halo ketones.

To increase the range of viable substrates, Kornblum later added a preliminary conversion of the halide to a tosylate, which is a better leaving group, to the protocol, and using pyridine-N-oxide or similar reagents rather than DMSO.

[5] The Ganem oxidation built on this latter modification, expanding on the use of various N-oxide reagents.