Formation of hydrates from aldehydes/ketones and H2O
Description: Addition of water to an aldehyde or ketone results in the hydrate [otherwise known as a “geminal diol”]
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My questions is that if ketone is reacting with water how to know whether my product will be “hydration” or the “Oh2” be as a leaving group, i get it mix up alot.
Generally with ketones equilibrium doesn’t favor the hydrate. It’s rare to see questions where you’re expected to draw the hydrate, and if that is the case, it would generally be with an aldehyde
Hydration reaction of carbonyl is the fundamental rule toward the synthesis of carboxylic acid
How would the mechanism change if this reaction were under basic or acidic conditions?
Hi Carrie, the difference is one extra step.
Under basic conditions, HO- would attack the carbonyl carbon in an “addition” step. Then in the second step, the resulting O- would be protonated by water to give OH
[2 steps]
Under acidic conditions, you’d protonate the carbonyl oxygen, which makes it a better electrophile. Then, water would attack the carbonyl carbon. Then, there’s be a deprotonation of the oxygen that just attacked (since now it’s R-OH2 + ) by a molecule of solvent (H2O) to give the neutral hydrate.
[3 steps]