Nitrosation to Make 1,2-Diketones

Nitrosation of enols is a route for making 1,2-diketones. In this reaction, the enol tautomer of a ketone reacts with sodium nitrite in hydrochloric acid. After hydrolysis, the product is a 1,2-diketone.

The reaction begins when hydrochloric acid converts sodium nitrite into an oxonium ion. The l...

The enol tautomer of carbonyl compounds can undergo a nitrosation reaction, where a second carbonyl group is introduced to form a 1,2-diketone. This nitrosation reaction occurs through a multistep mechanism.

Initially, sodium nitrite in hydrochloric acid produces the weak acid 'nitrous acid', which, on protonation, gives an oxonium ion.