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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: mana on August 21, 2017, 11:13:20 AM

Title: oxidation of c=c with MCPBA
Post by: mana on August 21, 2017, 11:13:20 AM
hi all
this reaction oxidate the double bond which is near CO2H, I think this C=C is not a conjugated double bond so it can be oxidated better than the other double bond
am I right? :P
Title: Re: oxidation of c=c with MCPBA
Post by: clarkstill on August 22, 2017, 06:02:56 AM
Looks good to me. mCPBA is an electrophilic oxidant so will oxidize the most electron-rich alkene, which you have correctly identified as the one not conjugated with the carbonyl. Were you asked to consider stereochemistry?
Title: Re: oxidation of c=c with MCPBA
Post by: mana on August 22, 2017, 01:55:46 PM
Looks good to me. mCPBA is an electrophilic oxidant so will oxidize the most electron-rich alkene, which you have correctly identified as the one not conjugated with the carbonyl. Were you asked to consider stereochemistry?
thank you for your answer, honestly I didn't consider stereo chemistry but I guess the epoxide must form on less crowded face of the molecule
Title: Re: oxidation of c=c with MCPBA
Post by: rolnor on August 22, 2017, 02:40:04 PM
The ketone can undergo the Baeyer-Villiger rearangement but that reaction is probably slower than epoxidation. There are example of that in wikipedia when hydrogen peroxide is more selective for forming epoxide in prescence of ketone compared to peracetic acid wich gives the rearranged product.
Title: Re: oxidation of c=c with MCPBA
Post by: AMDS1987 on September 02, 2017, 06:54:10 PM
Rolnor is right, Baeyer-Villiger will be competing with epoxidation, and it tends to give 80% of product from Baeyer-Villiger and 20% of epoxidation product. If you really want to make an epoxide for that molecule you can consider more powerful peroxyacid like trifluoroperoxyacetic acid.