1CHM 2212-Organic Chemistry II Name________________________(1)March 1, 2002Quiz #7 (25 points)(Covering material through section 15.13)1. (6) When nitrobenzene is brominated, the –Br group is directed to the meta position:NOOBr2FeDNOOBrVery little of the ortho or para product forms. The reason for this is that the intermediate carbocation (arenium ion) formed from attack of the "Br+" at the ortho or para positions have three resonance contributors each, just like for meta attack, but one of them is deemed to be unstable relative to the others. Draw this particular resonance contributor for either ortho or para attack.22. (6) We learned that a subsituent on an aromatic ring can operate electronicallyvia either an inductive effect, resonance effect, or both. Experimentally it is knownthat p-nitrophenol (pKa = 7.14) is more acidic than m-nitrophenol (pKa = 8.39).What does this say about how the NO2 group is operating electronically in thesetwo substituted phenols? Support your answer with resonance structures of theconjugate base form of the phenols.O–O2Nconjugate base ofp-nitrophenolO–conjugate base ofm-nitrophenolO2N33. (12) Outline how each of the following compounds could be made starting from
View Full Document
Unlocking...