Zhang,,
Spring2010
CHEM 3311,Professor
Thirdhourexam,April 15,2010
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ID;
Student
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1)
This is a closed-bookexam.The
useof notes,models,calculators,
scratchpaperwill not be allowed
during the exam. Pleaseput all
your answerson the test. Use the
backsofthe pagesfor scratch.
PartialPeriodicTable
8A
IA
I
H
3
-'i
1,1
' )A
4
Be
1l
T2
Na Mg
1A
5
o
B
r3
A1
6A
4A
C
7
N
8
o
r6
1t
t+
r
7A
9
F
I/
S
r-l
3-s
Br
)J
I
He
10
Ne
18
Al'
are oxidations[O], reductions[H] or
1. (12 pts) Indicatethe following transformations
neitherfNl.
^ \a--(
--------+.:.-X,..
OH
I
LNl
b^l
\.,,
c. /\a
t*l
Br
t4
d Iil
LOJ
\.,4..
2. (12 pts) For eacliofthe lbilowing pairsof compourds,indicatewhich is the stronger
base,and which is the strongernucleophile.The solventis indicatedbelow the structures.
Each box should have a 1 or a 2 written inside.
Stronger
Base
a.
/-o-
F3cl\o1
in ethanol
b.
2
l
F
4
2
in water
"
A,^o
Stronger
Nucleophile
w w
w r
-f"
12
in n-butylalcohol
in f-butylalcohol
Pase2'6
3. (15 pts)Draw the singlemajorproductof eachof the followingreactions,showing
is formed,showonly one
stereochemistry
usingwedgesanddashes.
If a racemate
enantiomer
ofthe product,andlabelit "rac". All thereagentsareshownabovethe
reactionsarrowsandthe solventsareshownunderthe arrows.
" -G''
NaCN
--=---------D
o
{+ (DlvrSo)
9/A
o
^ _5.^ (^,/
,\nq
---.-_->
Ar^o,
QH2Ql2
Kl\4n04,NaOH
--------------Hzo
c. HoYoH
"oilot
Jtt:'
CX;C@
H
J,
funp^
_______>
cH30H
A compounds,
indicatewhichhasthe highestor lowest
4. (12ptsl For theI'ollowingGr-oup
indicatewhichhasthe highestor lowest
boilingpoint (B.P.):lbr CroupB compounds,
havea numberwritteninside.
solubilityin water.Eachbox sho.uld
A. ,/',\o,'\
-l^on
,,'\r^OU
34
1
t
,,.....,,'-
a\Aon
12 34 'W
,,\,r^-Aon
$o'
Highest
B-P,
Lowest
B,P.
Highest
solubility
in H2O
Lowest
solubility
in H2O
w w
w
Pase3./6
5. (16pts)Proposereagents
for accomplishing
eachof the followingreactions.
Makeyour
reactionsefficier.rt(i.e. the targetproductshouldbe the major product).Assumechiral
starling rnaterialsand productsare single pureenatiomersunlessthev are labeled"rac".
l) c,'s-.t,
" J.-r(
C)
----+
z)Nacu
b Arr
CA2T7,Z"fcu
---_-_---_->
c' zLi
z\,/'Br
________>
iN...-,
) ^ 'u
/\4Li
.L*-''
,\>
o
d
S,Hr,,d'
AioH
--rA*
is allowedto reactwith sodium
6 . (12pts)a) When(1R,25) 1-bromo-2-methylcyclohexane
methoxidein methanol,threeproductsareformedin variousamounts.Oneproductis ar.r
ether,and two productsare differentalkenes.Give the structuresof the three products,
whereappropriate,and circle the major alkene
showingstereochemistry
t
i
i
Pr
-Z\.$ '"'
I
\,/
I
^. . U^- . . Na +
UHr
-------->
CH3OH
;tl
tl
ll
Iv\
d
Palre'1,6
b) Carefullydraw a pictureofthe transitionstateleadingto the major alkeneproduct.Be
structure(equatorialvs axial substituents)of the
sure to indicate the stereochemical
transitionstateandiustifv vour answerwith onesentence.
lbcH,l+ The*ransi\on
da.\e lea[rnoto tha
a\kanerol\\ho \ouost
tvrostetab\e
and the hYlrE'enbeg
ift nnorgy
f€wveJ Mo5+be anf; to the
bron'tiJ.e lu*E
J-r
7. (21 pts) Propose a synthesisof each of the following targets, starting with any organrc
moleculescontaining five (5) carbonsor less, and any necessaryinorganic reagents.For
any unstable organic reagents(e.g.Grignard, radical, carbene)that you want to use,
you should show their synthesis (how to prepare them). Try to make your synthesis
efficient(i.e. the targetshouldbe producedin the highestpossibleyield). More than one
step may be required and you should draw all the intermediates.HINT: Try to work
backwardsfi'oln the talget to the srnallerstartingmaterials,using reactionsyou know.
F'
z"fc'
LH'T7.,
____________>
+
Pase5i6
^l
"
A,,^"^-A
-+
AioH
/Vc,J-tt
t-r R,NI; I
e. ,-r-^t-;t
L.^".-,^
/,\,..\-MqF)r
t-
/\v^o
CN
OH
+
-.----->
tI
I
,//-\-
1_J
wl-_c'H>
I
vt2
eN
/tC/'l
_-4
+
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