[chynagrl]

Hi,

I am currently doing a problem on aldol condensations. Why do they actually work successfully? I mean, for instance, that the product is extremely stable or something like that. I know that in the dehydration reaction following aldol condensations, an OH group is the leaving group. The OH group is a terrible leaving group, but it still leaves because the product, a conjugated product, is extremely stable and therefore drives the equilibrium towards the product side of the reaction.

Thank you so much!
chynagrl

[sjb]

Typically you run aldol condensations with catalytic acid, in this case the leaving group is actually H₂O, which is actually pretty good as leaving groups go...

[Med90]

thank you for the information,
I would like to add little more. As you said OH is good leaving group. It is eliminated as H2O in aldol condensation, but it needs, alpha hydrogen. Sometime, because of dehydration, alpha hydrogen is lost and H2O can't be eliminated giving the OH containing finalcompound instead of alpha beta unsaturated compound.

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