What is the order in terms of decreasing acidity?

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1 Answer
Apr 20, 2018

Well, the more carbonyl groups proximate to the carbon which bears the acidic protons....

Explanation:

...the more that carbanion should be stabilized upon abstraction of that proton. Given this rule of thumb, the order or acidity...with the LEAST acidic molecule to the LEFT should be:

.......... stackrel(IV, II, I, III)rarr ..........
"order of increasing acidity"

The carbanionic charge of molecule IIIis potentially distributed over SEVEN centres, and thus should be the most acidic.

Note that as a chemist, as a physical scientist, you should put forth some data in support of your argument, and quote the pK_a values of each species. For cyclohexane, the value will be around 50...I think there is such a table of pK_a of carbon acids in March...