organic question

[demonicr]

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hi, i have a question. on an aromatic compound, lets say a phenol. and lets say say we have an electron withdrawing group attach to the ring ( a carbonyl carbon). is phenol will be most acidic when the substiuents will be at what postion, ortho, mete, or para, and why? any help is appreciated

 

[Sprgrover]

It seems you are familiar with the effect of electron withdrawing groups and acidity so I'll jump right in. Out of the three possible positions, ortho, para, and meta, the ortho and para ones will result in the phenol being the most acidic. The reason for this is because at these positions the compound is better able to manage both resonance and the inductive effects of the EWG. As far as which one creates the most acidic compound, I would venture to say ortho simply because the EWG and the alcohol are so close it's just a short jump for the OH's electrons to be inductively withdrawn.

 

[demonicr]

cool, thanks a lot, thats what i thought the answer was too. its just that i put ortho and acethedat.com say it was para. i think im going to stay away from that website, its just gonna confuse me more...

 

[DrTacoElf]

Its all about resonance. Draw it out. The 1 of the lone e- pairs on the oxygen can be cycled aroudn the ring for O or P positions and create a double bond to oxygen. Meta does not allow this.