学业指导中心学习2014 6有机化学乙exercise 7.pdfVIP

OrganicChemistryExercise7Nov.22thwithin20min

1.Predicttheeffectthesubstituentattachedtothebenzeneringbelowwouldhaveonelectrophilicaromatic

substitutionreactions?

A.ortho/paradirector,activator

B.ortho/paradirector,deactivator

C.metadirector,activator

D.metadirector,deactivator

2.IntheFriedel-Craftsalkylationofbenzene,dialkylationisoftenasignificantby-product.IntheFriedel-

Craftsacylationofbenzene,diacylationisnotasignificantby-product.Whichofthefollowingisthe

primaryreasonforthisdifference?

A.Alkylgroupsactivatetheringtofurthersubstitution,acylgroupsdeactivateit.

B.Alkylgroupsarelessstericallyhinderedthanacylgroups.

C.AcylcationsaremoredifficulttomakewithLewisacids.

D.Unlikeacylcations,carbocationscanundergorearrangements.

3.Whichisomerofdichlorobenzenegivesasinglemononitrationproduct?

A.ortho

B.meta

C.para

D.noneofthem

4.SalicylicacidreactswithtwoequivalentsofICltogiveoneoftheproductsbelow.Whichoneisit?(Hint:

ClismoreelectronegativethanI.)

A.A

B.B

C.C

D.D

5.Identifythepreferredsite(s)ofelectrophilicattackonthefollowingcompound.

1

A.ortho/parapositionsonring1

B.metapositiononring1

C.ortho/parapositionsonring2

D.metapositiononring2

6.Whichofthefollowingisthebestmethodtomakemeta-bromoethylbenzenefrombenzene?

A.