Tribromomethyl ketone cleavage

While the haloform reaction normally only cleaves methyl ketones because of the structural requirements for the a,a,a-tribromomethyl ketone to induce fragmentation, the strain release that accompanies cleavage of a cyclobutanone permits extension... 

Acid-Catalyzed Enolization of an Aldehyde or Ketone in Aqueous Solution 899 Acid-Catalyzed Bromination of Acetone 901 Cleavage of a Tribromomethyl Ketone 903... 

The cleavage of the carbon-carbon bond occurs by a two-step mechanism in which hydroxide ion attacks the carbonyl carbon atom to give a tetrahedral intermediate that subsequently releases the tribromomethyl carbanion. If iodine reacts with a methyl ketone, iodoform, CHI3, forms. It is a bright yellow, insoluble solid. 

---