Diketone

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A diketone is a molecule containing two carbonyl groups. One such example is acetylacetone.

A diketone is an oxygen nucleophile.

1 Reactions
- 1.1 Nucleophilic addition
2 Health
3 References

[edit] Reactions

Diketones react similarly to ketones or aldehydes.

They also readily undergo enolization, and many 1,3-diketones are thermodynamically stable as conjugated enols or even enolates. One such is ascorbic acid, which is more stable as an enol(ate) rather than a diketone. The enol group gives off a proton, and the charge of the resulting enolate is delocalized along the ketone-enolate system. This delocalization stabilizes the enolate counterion and makes it less likely to regain the proton, which makes ascorbic acid acidic. Also, if a diketone has ketone carbonyls separated only by one carbon, the alcohol hydrogen in the corresponding enol is hydrogen-bonded to the carbonyl oxygen, giving a six-membered ring (-RC=CH-OH..O=CR-).

[edit] Nucleophilic addition

See also: Nucleophilic addition

diketone + nucleophile → tetrahedral carbonyl addition compound

diketone + alcohol + acid or base ↔ hemiacetal
- hemiacetal + alcohol + acid catalyst ↔ acetal + water
- This is a carbonyl-protecting reaction.

[edit] Health

EU Commission has declared that diketones (for example acetylacetone, CH₃COCH₂COCH₃) are like dialcohols and hydroxyketones in that they are in vitro and in vivo genotoxic chemical substances and therefore have been forbidden as nutrition additives since 2005.^[1]