[orgstudy]

Hi ...

Question: Pic ...

i came up with 2 methods ... A & B

which one will be correct and why? 

[Honclbrif]

What's the Hg(II) doing?

[orgstudy]

well i dont know the that but i'm sure the rxn will proceed like one of the ways i posted

My guess is that its short form of oxymercuration demercuration rxn.
but i'm not sure ...

[silvi]

I think the first one is correct, because the product is a well-conjugated ketone.
Mercury II forms an cyclic ion, like an epoxide, then water opens the cycle and then mercury ion is eliminated.

[jake.n]

Both of your mechanisms are incorrect for your reaction conditions.  In acidic conditions, you will certainly not be forming an intermediate carbanion.

I think orgstudy is right and that this is simply oxymercuration/demercuration where the product tautomerizes.  In that case, you should look at which enol is the Markonikov product

[orgstudy]

Both of your mechanisms are incorrect for your reaction conditions.  In acidic conditions, you will certainly not be forming an intermediate carbanion.

I think orgstudy is right and that this is simply oxymercuration/demercuration where the product tautomerizes.  In that case, you should look at which enol is the Markonikov product

I read same mechanism i gave above on internet but that was for HC≡CH

and why this mechanism is not possible?
will it be possible if H+ attacks before H2O ? (because unsaturated system give electrophilic addition first )

[jake.n]

Yeah, basically just do the electrophillic addition first.  It's not very likely that you'll be generating carbanions in sulfuric acid, is all I'm getting at.

Whether the mercuric ion or the hydrogen ion act as the acid in the electrophillic addition, you definitely want to do that step.

[orgstudy]

Yeah, basically just do the electrophillic addition first.  It's not very likely that you'll be generating carbanions in sulfuric acid, is all I'm getting at.

Whether the mercuric ion or the hydrogen ion act as the acid in the electrophillic addition, you definitely want to do that step.

Well that solves the question

answer must be A so that carbocation is stabilized ...

[orgstudy]

Thanks all for help