CHMB42H3 Chapter 18: CHMB42 Chapter 18.doc
Document Summary
Or group of the ester also has a lone pair that can be delocalized onto the carbonyl oxygen (competes). If the a -carbon is between two carbonyl groups, the acidity of an a -hydrogen is even greater because the electrons left behind when the proton is removed can be delocalized onto two oxygen atoms. Keto-enol tautomers: a ketone exists in equilibrium with its enol tautomer. For most ketones, the enol tautomer (-oh and c=c) is much less stable than the keto tautomer (c=o). Phenol is an enol tautomer and is more stable than its keto tautomer because it is aromatic and the keto tautomer is not. Keto-enol tautomerization or enolization: interconversion of the keto and enol tautomers: mechanism for base-catalyzed keto-enol interconversion, hydroxide ion removes a proton from the a -carbon of the keto tautomer, forming an anion called an enolate ion.
