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Name:________________________________________________________________________________________________________ Last First MI
Chemistry233-001Exam2
Spring2017 Dr.J.OsbournInstructions:Thefirst15questionsofthisexamshouldbeansweredontheprovidedScantron.YoumustuseapencilforfillingintheScantronsheet.Ensureallerasuresarecomplete.Anyquestionsleft blankwill bemarked incorrect.Anyquestionwithmultiple answers selectedwill bemarkedincorrect.Answertheremainingquestionsontheexamitself.Showallworkandprovidecompleteexplanations.Pleasewriteyournameon:
• Thefirstpage(ExamCoverPage)• Thesecondpage(GradingPage)• TheScantronSheet–CircleyourLastName
PleasebubbleinyourWVUStudentIDNumberonyourScantronsheet.
ThePeriodicTable
*Pleasedonotripoffthiscoversheet*
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Name:__________________________________________________________________________________________________________ Last First MIGradingPage(Exam2):
Page Points Possible Points Earned
Multiple Choice (3-5) 30
6 17
7 18
8 17
9 18
TOTAL 100
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MultipleChoiceChoosetheonebestanswerforeachofthefollowingquestions.Usingapencil,recordthisanswerontheprovidedScantronsheet.(2pointseach)
1. Whichofthefollowingisthemoststablechairconformationforthecompoundshownbelow?
2. Whatistheconfigurationatthechiralcenterinthemoleculebelow?
a. R-configurationb. S-configuration
3. Whatisthemaximumnumberofstereoisomersforthecompoundshownbelow?
a. Twob. Fourc. Eightd. Ninee. Sixteen
4. Whichoneofthefollowingleadstothemostexergonicreaction?
a. AnegativeΔHandanegativeΔS.b. ApositiveΔHandapositiveΔS.c. AnegativeΔHandapositiveΔS.d. ApositiveΔHandanegativeΔS.
a b
c d
H
N
Br
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5. Considerthepartialreactionmechanismshownbelow.Whichofthefollowinghasthecorrectmechanisticarrows?
6. Whatmechanisticstep(s)is/arerepresentedinthereactionshownbelow?
a. Protontransferb. Nucleophilicattackc. Lossofaleavinggroupd. Nucleophilicattack&lossofaleavinggroupe. Electrophilicattack
7. WhichNewmanprojectionbelowisananticonformation?
c
a
b
OH H Br OH2 + H2O+ Br
OH H Br OH2 + H2O+ Br
OH H Br OH2 + H2O+ Br
OH H Br OH2 + H2O+ Brd
O HO
H
H
OH
CH2CH3
HHCH3
H HCH2CH3
HHH
H3C H
a b c d
CH2CH3
HHH
H3C
H
CH2CH3
HHH
H
CH3
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Forquestions8-11,determinewhethereachmoleculeis:(a)Chiral,(b)Achiral,or(c)Meso-AchiralBubbletheseanswersinonyourScantronsheetforcredit!
Forquestions12-15,determinewhethereachpairofmoleculesrepresent:(a)IdenticalCompounds,(b)ConstitutionalIsomers,(c)Enantiomers,or(d)DiastereomersBubbletheseanswersinonyourScantronsheetforcredit!
O
HOOCCOOH
OH
OH
ClCl
OH
CH3
H CH3
8. 9. 10. 11.
12.
13.
14.
15.Cl
H OH H ClOH
and
and
and
and
OH OH
Cl
OHOH
Cl
H CH3
Br Cl
H3C Cl
H Br
CH3 CH3
HHOH OH
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CompletionSectionAnswertheremainingquestionsinthespacesprovided.Showallworkandprovidecompleteexplanations.16. ProvideIUPACsystematicnamesforeachcompoundshownbelow.IncludeR/Sonlywhere
appropriate.(3pointseach)
17. LabeleachalkenebelowasE,Z,orneither.(1pointeach)
18. Usingthetemplateprovided,convertthestructureshownbelowtoaFischerprojectionthen
drawtheenantiomerofyourFischerprojection.(4points)
19. Determinethedegreeofunsaturationpresentineachformulaorstructureshownbelow.(1pointeach)
a.
b.
H
Cl
CH2CH3
CH2CH3
H BrH CH3
H3C
F
OHH
Br
H3C CH2CH3
OHH
CH2CH3
Enantiomer
O C6H12 C5H13NO
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20. Labelthemajorform(s)ofstrain(angle,torsional,steric)presentintheprovidedconformationofeachcompoundshownbelow.(1pointeach)
21. ConvertthemoleculeshownbelowtoaNewmanprojectionviewingalongtheindicatedbond.(4points)
22. a.DrawthehighestenergyNewmanprojectionabouttheC1-C2bondof1-bromopropane.(3points)b.Iftherelativeenergyoftheaboveconformationis5.1kcal/mol,whatistheenergycostassociatedwithaBr/CH3eclipse?(1point)
23. Drawbothchairconformationsforthecompoundshownbelowusingthetemplatesprovided.
Putthe–CH3onthecarbonhighlightedwiththegraycircleandorientyourothergroupsbasedonthatreferencepoint.Circlethechairconformationthatislowestinenergy.(5points)
24. Drawachairconformationthatmeetsthefollowingcriteria:(2points)• AxialOHatC1• EquatorialCH3atC5• BratC2thatistranstoCH3
CH3
CH3
CH3H
H
HH
H H
H
H H H
HHHH
CH2CH3H3C
HO
H Cl
H
CH3
Br
12
3 4 5
6
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25. Predicttheproduct(s)foreachreactionstepbelowbytrackingtheelectronflow.(2pointseach)
26. LabeleachmechanisticstepbelowasaNuattack,protontransfer,lossofleavinggroup,orcarbocationrearrangement.(3points)
27. Determinewhethertheindicatedatomineachspeciesshownbelowwillactasanucleophile,electrophile,orboth.(1pointeach)
28. Showtwodifferentrearrangementproductsforthecarbocationshownbelow.Circletherearrangementproductthatispreferred(morelikelytoform).(4points)
29. Forthereactionshownbelow,whatisthesign(+or-)fortheentropyterm(ΔS)?(1point)
a.
b.
c. Cl
+ OH
O
O OH
O
O
OH
OO
HO
O
O+ HO
NaOH
H
O
+ +ΔS -ΔSor
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30. Considerthemoleculeephedrineshownbelowandanswerthefollowingquestions.(9points)
a. What is the maximum number of stereoisomers?
b. Draw the 1R,2S stereoisomer. c. Draw the enantiomer of the stereoisomer from b.
d. Draw a diastereomer of the stereoisomer from part b.
e. Explain exactly what a bottle of racemic ephedrine would contain.
31. Drawanopticallyactiveandopticallyinactivestereoisomerforthecompoundshownbelow.
(4points)
32. IdentifyeverychiralcenterinVitaminD(shownbelow)usinganasterisk(*).(3points)
33. Drawtheenantiomerofthechaircyclohexaneshownbelow.Youmustdrawtheenantiomerasachair!(2points)
HN
OH
1 23
OH
OH OH
optically active optically inactive
HO
Br
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