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Name:________________________________________________________________________________________________________ Last First MI
Chemistry233FinalExam–NewMaterialPractice
Theproblemsincludedaretohelpprepareyouforthenewmaterialthatwillbeonthefinalexam(i.e.stuffwehavecoveredsinceyoutookexam3).Theactualfinalexamwillbecumulativeandwillcontainmaterialthatwecoveredthroughoutthecourseofthesemester.Atpresent, Iamestimatingthat therewillbe~1/3newmaterialwhile theother2/3willbeold,cumulativematerial.The final examwill likely containmoremultiple-choice questions than usual. This could includematching.Forexample, Imightgiveyoua listofreactionswithblankarrowsandareagentbank.Youwouldthenneedtochoosethecorrectreagentfromthebanktocarryoutthereaction.Seetheexampleinquestions1-8.Iamplanningtomakethebulkofthewritten(completion)sectionnewmaterialfromchapters10and11,whichmostoftheoldmaterialwillbepartofthemultiplechoicesection.ThePeriodicTable:
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Usingthereagentbankprovided,selecttheappropriatereagenttocarryouteachofthefollowingreactions.
9. PredicttheproductandshowthefullelectronpushingmechanismfortheSN1reactionbelow.
Reagent Bank
Br ?
I?
Br ?
1.
2.
3.
4.
? O5.
?6.
mCPBA
1. TsCl Pyridine2. NaCN NaCN
KOtBu1. BH32. NaOHH2O2
A B C
D E
AD
OH?
AB
AC AE
SCH3
NaSCH3
OH
NaOH
H2O
Cl
CN
?7.
?8.Cl
OH
Cl ClCl
H2SO4CH3OH
NaOHHeat
BDBC BE
HCl
Cl2
Br CH3OHSN1
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8. Predictthemajorproductforthereactionshownbelowandthendrawthecompleteelectronpushingmechanism.Includeinitiation,propagation,andterminationsteps.YoucanjustassumeNBSgiveasteadyconcentrationofBr2.
9. Althoughthecompoundbelowdoesnothaveanyβ-hydrogen,itreadilyundergoeselimination,eveninthepresenceofaweakbasesuchaswater.1.Predicttheeliminationproduct.2.Explainwhythiseliminationissoenergeticallyfavorable.
10. Ranktheindicatedbondsinorderofincreasingbondstrengththenprovideanexplanationforyourranking.
NBSlight
Br
HH H H
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11. Predictthemajorproduct(s)foreachofthereactionsshownbelow.Indicatetheoperativemechanism(SN1,SN2,E1,orE2)andshowstereochemistrywhereappropriate.
BrNaCNDMF
I OH
Br
H2O
Cl
H3CO
H3COH
Cl NH2
DMSO
mechanism
mechanism
mechanism
mechanism
mechanism
a.
b.
c.
d.
e.
f.
H3C Imechanism
O
Cl
O
BrCH3OHHeat
Br
DMF
mechanism
mechanism
mechanism
g.
h.
i.
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12. Thealkyliodideshownbelowhasthepotentialtoformfourdifferentproductsuponelimination.Draweachoftheseproductsintheboxesprovided.
a. WhichonewouldbethemajorproductifNaOtBu(bulkybase)wereusedasthebase?b. IfthereactionwerecarriedoutinCH3CH2O-andacetone,whatmechanismwould
predominate?c. WhichonewouldbethemajorproductifCH3CH2O-wereusedasthebase?
13. Provideareasonablesynthesisforthecompoundshownbelowusingtheprovidedstarting
materialandanyotherorganicorinorganicreagents.
14. Circlethefasterreactionineachsetandprovideaverybriefexplanationforyourchoice.
Br
A B C D
CN
OTsNaBr
Acetone OTsNaIH2O
vs
Br H2O H2OBrvs
