Chemistry 233-001 Exam 2
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Page 1 of 9 Name: ________________________________________________________________________________________________________ Last First MI Chemistry 233-001 Exam 2 Spring 2017 Dr. J. Osbourn Instructions: The first 15 questions of this exam should be answered on the provided Scantron. You must use a pencil for filling in the Scantron sheet. Ensure all erasures are complete. Any questions left blank will be marked incorrect. Any question with multiple answers selected will be marked incorrect. Answer the remaining questions on the exam itself. Show all work and provide complete explanations. Please write your name on: • The first page (Exam Cover Page) • The second page (Grading Page) • The Scantron Sheet – Circle your Last Name Please bubble in your WVU Student ID Number on your Scantron sheet. The Periodic Table *Please do not rip off this cover sheet*
Transcript of Chemistry 233-001 Exam 2
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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
