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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: miaou5 on May 03, 2012, 02:57:38 AM

Title: oxymercuration adds h and oh in a what configuration? syn or anti?
Post by: miaou5 on May 03, 2012, 02:57:38 AM

i know that hydroboration adds h and oh to an alkene in a syn configuration, but how about oxymercuration? is it syn or anti, or racemic? thanks!

Title: Re: oxymercuration adds h and oh in a what configuration? syn or anti?
Post by: discodermolide on May 03, 2012, 05:30:27 AM

Quote from: miaou5 on May 03, 2012, 02:57:38 AM

i know that hydroboration adds h and oh to an alkene in a syn configuration, but how about oxymercuration? is it syn or anti, or racemic? thanks!

It gives a Markovnikov addition. It must be racemic and as you are adding OH and H how can it be syn or anti?

Title: Re: oxymercuration adds h and oh in a what configuration? syn or anti?
Post by: orgopete on May 03, 2012, 09:09:50 AM

The addition is an anti-addition. The product is a mercury alcohol. The demecuration reaction has been reported to be a radical reaction. Therefore, the relative stereochemistry created in opening the mecrurinium ion is lost during the reduction step. So, it is the last step that loses the syn/anti distinction, unlike hydroboration/oxidation.

Title: Re: oxymercuration adds h and oh in a what configuration? syn or anti?
Post by: miaou5 on May 06, 2012, 01:03:27 PM

thank you so much pete! that makes sense. (: