ketocarbon

Ketocarbon is not a standard IUPAC term, but it is used in some chemical discussions to refer to the carbon atom at the center of a ketone's carbonyl group, or more loosely to the ketone functional group itself. The ketocarbon is ordinarily sp2-hybridized and lies in a planar arrangement with the adjacent carbon substituents. It is the electrophilic center of the molecule.

In a typical ketone such as propan-2-one (acetone), the ketocarbon is bonded to two carbon substituents and to a doubly bonded oxygen. The carbonyl C=O bond length is about 1.20–1.23 Å, and the bond angle around the carbon is close to 120 degrees. Resonance with a partial negative charge on oxygen reinforces the polarity of the C=O bond, making the ketocarbon susceptible to nucleophilic attack.

Reactivity: Nucleophiles add to the ketocarbon, and reduction converts it to alcohols. Oxidation is limited for ketones without cleaving the carbon framework. Ketones participate in aldol condensations, acyl-transfer reactions, and various reductions to secondary or tertiary alcohols. They are common as solvents, intermediates, and metabolic products, including biological ketone bodies such as acetoacetate and acetone in certain states.

Notes: The term ketocarbon is relatively uncommon and may cause confusion with other carbonyl terms. When discussing ketones, it is clearer to specify the functional group (R-CO-R') and the carbonyl carbon. The concept remains central to organic chemistry, serving as the electrophilic site for many reactions.