Why enol content of ethyl acetoacetate is more in toluene than water?
The extent of enolization is affected by the solvent, concentration and temperature. Ethyl acetoacetate has enol content of 0.4% in water and 19.8% in toluene. This is because water reduces the enol content by hydrogen bonding with the carbonyl group making this group less available for intramolecular hydrogen bonding. The effectiveness of intramolecular hydrogen bonding in stabilizing the enol, with respect to the keto form is thus seen on varying the solvent and particularly on transfer to a hydroxylic solvent.