[GuitarHero]

Hi,
I'm having some difficulty figuring out the mechanism for this reaction. A compound reacts with sulfuric acid in water to create 2 enantiomers. I just need some help figuring out what the nucleophile is (Oxygen?) what the leaving group is, and the mechanism...
Any help at all would be appreciated!

(Image attached)

[discodermolide]

Hi,
I'm having some difficulty figuring out the mechanism for this reaction. A compound reacts with sulfuric acid in water to create 2 enantiomers. I just need some help figuring out what the nucleophile is (Oxygen?) what the leaving group is, and the mechanism...
Any help at all would be appreciated!

(Image attached)

Hydration of the double bond to give the secondary alcohol.
There is no real leaving group as such, you can guess what the nucleophile is, not oxygen!

[GuitarHero]

Hydration of the double bond to give the secondary alcohol.
There is no real leaving group as such, you can guess what the nucleophile is, not oxygen!

Okay, that makes sense so far. So am I correct in assuming that the OH can attack from either side, making this an SN1 mechanism? But then was the sulfuric acid just thrown in there to confuse us?

[discodermolide]

Hydration of the double bond to give the secondary alcohol.
There is no real leaving group as such, you can guess what the nucleophile is, not oxygen!

No, the acid protonates the double bond. If you imagine an epoxide with an H+ instead of an oxygen, that is the intermediate. This "ring" is opened by water to give the alcohol.

Okay, that makes sense so far. So am I correct in assuming that the OH can attack from either side, making this an SN1 mechanism? But then was the sulfuric acid just thrown in there to confuse us?

[orgopete]

In sulfuric acid, the HO- concentration would be zero. Water will be you nucleophile and you will need one additional step to get a neutral alcohol. Bisulfate could also be a nucleophile, but that is generally for less reactive alkenes. In those cases, hydrolysis of the sulfate ester is necessary to get an alcohol. That need not apply here.

[discodermolide]

In sulfuric acid, the HO- concentration would be zero. Water will be you nucleophile and you will need one additional step to get a neutral alcohol. Bisulfate could also be a nucleophile, but that is generally for less reactive alkenes. In those cases, hydrolysis of the sulfate ester is necessary to get an alcohol. That need not apply here.

He does not mention the H2SO4 concentration,
This reaction is the hydration of a double bond to a secondary alcohol, quite simple