# Which of the following compounds possess more than one percent enol content? [closed]

Which of the following compounds possess more than one percent enol content?

I understood that stability of enols are dependent on the hydrogen bonding in the compounds. But here, what is the significance of more than one percent enol content?

• I would like to express my disagreement with the assertion that the stability of enols would mainly be dependent on inter- and intra- molecular hydrogen bonding. Mar 26 at 9:15
• @user79161 I mean that h-bonding is one of the factor that could be used for determining the stability of Enols. It need not be the primary factor. Mar 26 at 9:53
• Especially because of the nice representations of the formulae (for easier reading, consider to rotate labels, though [entry i]), a more useful question were the comparison of the entries by line to justify which ones are more likely to enolize, than others -- for example in the line of a to d. For some, $\log{}K$ may depend on the molecule's structure as well as (if there is) the solvent molecules. Or -- guessing -- are you literally looking for a tautomer database example? Mar 26 at 9:57
• chemistry.stackexchange.com/questions/18904/… This might help you;@Ron's answer was very extensive. Note that, as Buttonwood pointed out, a fruitful exercise would be to compare likelihood of enolization. To compare the respective percentages would need you to carry out an experiment and interpret that data. Mar 26 at 12:48

All the compounds that have a relation $$\alpha-\beta$$ between the carbonyl groups. The hydrogen between two $$\ce{CO}$$ is very acid because two electrowithdrawing remove electron density from the $$\ce{C-O}$$ bond. Therefore for this kind of compound the most stable for is the enol. In Organic Chemistry this is very useful in creating new carbon-carbon bonds in mild conditions like in aldoholic reactions, Michael reactions and so on. See the very good book of Marc Loudon, Organic Chemistry.