Acidity of enols

Enols (pATa ca = 11-12) are usually more acidic than alcohols [e.g. EtOH pATa (H2O) = 15.9 ] but are less acidic than phenols [e.g. PhOH pATa(H20) = 9.95 ]. The acidity of enols (and the basicity of the corresponding enolate) is surprisingly uniform when considering the relative acidity of the carbonyl derivative. The majority of enols derived from saturated aldehydes and ketones have pATa ca 11-12. For simple aldehydes and ketones, such as acetaldehyde (45) and acetone (45 ), their enol acidity (pATa ) in water is similar even when their keto acidity (pATa ) is moderately different. It is interesting to note that relative enol stability (pATs) plays little or no role in the relative acidity of enols for example, as is the case of 45 and 45. ... 

As Sections 20.3 through 20.12 demonstrate, the importance of enolates in organic chemistry lies in their synthetic applications, especially in procedures involving the formation of carbon-carbon bonds. What about enols—the conjugate acids of enolates ... 

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