[insertwittyname]

If in a ketone, two different enol forms are possible, eg: can give both and , which is major product in acidic medium?
I think the elimination of H should follow saytzeff rule, IE should be in the majority, as abstraction of that H by acid ought to be easier. Would I be correct?

[orgopete]

That would be my guess as well. Under basic conditions, you could form kinetic product determined by greater acidity of methyl group. Under acid conditions, I would assume electron donation would prevail to give the more substituted enol as an E/Z mixture.

[zsinger]

Sterically hindered bases might give the kinetic product instead of the thermodynamic product, so watch that!
        -Zack

[orthoformate]

it would depend when you measured the concentrations in aq. acid correct?

[Vidya]

It will depend on the stability of the enolate ion formed during the mechanism.Electron donating groups will destabilize it and electron withdrawing groups will stabilize it.