Reactivity of Enols a-Substitution Reactions

Draw structures for the enol tautomers of the following compounds, and identify all acidic hydrogens in each  

Draw structures for all monoenol forms of the following molecule. Which would you expect to be most stable Explain. 

What kind of chemistry do enols have Because their double bonds are electron-rich, enols behave as nucleophiles and react with electrophiles in much the same way that alkenes do. But because of resonance electron donation of a lone-pair of electrons on the neighboring oxygen, enols are more electron-rich and correspondingly more reactive than alkenes. Notice in the following electrostatic potential map of ethenol (H2C=CHOH) how there is a substantial amount of electron density (yellow/red) on the a carbon. 

CHAPTER 17 CARBONYL ALPHA-SUBSTITUTION AND CONDENSATION REACTIONS 

General mechanism of a carbonyl a-substitution reaction on an enol. The initially formed cation loses H to regenerate a carbonyl compound. 

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