CH 243 ORGANIC CHEMISTRY 1 (FALL
(October 23,2008)
Name:
-
2
Recitation Section:
(Please print)
Pledge: I pledge my Honor that I have abided by the Stevens Honor System. _
C
__
Answer the following questions. Please indicate the letter/ number choice of your answer clearly.
Each problem is worth 4 points unless otherwise indicated.
1. In each of the following pairs, indicate which reacts faster. (2 points each)
(i) On being treated with HBr (a) 1-butanol (b) 2-butanol
3f 0>
c-c-c-c
cavc-c-c-c.
"' "
\e>
QU
(ii) On being treated with HBr (a) 2-methyl-2rpropanol (b) 2-butanol
C - c - c i-
c-c-c-c
(iii) On being treated with HBr (a) 2-methylbujane (b) 2-butanoPM
c-c-c-c
c-c-c-c
O tA
(iv) On being treated with HBr (a) 1-methylcyclopentanol (b) cyclohexanol
(v) In a reaction with Bra (with heat) (a) 2-methylpropane (b) butane
C-C-C
C-t-t-C
(vi) With sodium cyanide in DMSO (a) CH3CH2CH2<iH2Br (b) CH3CH2CH2CH2I
c-c-c-c-6r v °
c-c-c-c-x » »
(vii) Solvolysis hi ethanol (a) l-bromo-3,3-dimethylpentane (b) 2-bromo-2-methylpropane
c-c-c-^-c
c~£-C *><*
(viii) hi a reaction with 2-methylpropane in the presence of heat and light: ta) C12 (b) Br2
(ix) With potassium iodide hi acetone (a) 1-chlorohexane (b) 2-chlorohexane
Vli
c-c-c-c -c-c-o
c-c-c-c-c-c
(x) hi aqueous ethanol as a solvent, 1-chlorobutane with
(a) NaNa - sodium azide (b) NaOTs - sodium /?-toluenesulfonate
C- c- c-c - C\
2. Epoxidation describes a chemical reaction hi which the sp2 hybridized carbon pair (double bonded carbon
pair) reacts with a peroxy acid to form a three membered heterocyclic compound (with one O hi the ring).
Which of the following compounds gives a parr of diastereomers upon epoxidation with peroxyacetic acid,
CH3CO3H?
By cg-CH3CENCHCH2CH2OH
A) H2C=CHCH2CH2CH^>H
3. How many stereogenic centers are there in the following molecule?
OH
CH3
CH3
A only
C. three
D. four
r:
c ;4H
•c V
4. Which of the molecule(s) below is/ are achiral?
"
HO
OH
HO
I
OH
C'Gstt
OW
HO
nJ
.land II
/ e^
N
Br
W
m
IIandin
X-
Iandin
/
,<i- C
X only I
N
ow
*-
/. only III
Bonus Question: (2 points)
Indicate the absolute configuration(s) of the chiral carbon(s) in the achiral molecule(s) from problem 2 above
(Use labels 1, 2, etc. to indicate which carbon is which, in case there is more than one chiral carbon.)
C2 K
C3
D. There are no chiral carbons in an achiral molecule.
5. Which sawhorse drawing below represents the ena
projection below?
CO-H
CO,H OOMA
u
,.,^^_.
\
mer of the compound shown in the Fischer
H,N
FT
^
^
/COfeH
^ H.AOH
Ct> : H
^
S
/-
H^
^
NH
H^N-T^-H
HO/
Bonus Question: (2 points)
Which sawjiqrse drawing from problem 3 above represents an identical conformation as the compound
indicatgdin the Fischer projection?
_
O
^
6. Which of the following optically active unsaturated compounds of molecular formula C5HioO reacts with
one equivalent of hydrogen to give a saturated compound of molecular formula CsHnO; the hydrogenation
product is also optically active? ^Q\^ oh \ro\\
cv^cH
D) CH3CHCH2CH=CH2
B) CH3CH2CHCH=CH2
A)
C) frans-CH3CH=CHCH2CH2OH
OH
OH
•
7. How many monochlorination products o'fryou expect in the following reaction?
C -C
Vc-c-c
D. five
E. more than five
Bonus Question: (2 points)
How many of these monochlorination products are expected to be chiral compounds?
~~~^\>\'
A. j0ne J
B. two
C. three
D. four
E. more than four
8. Rank the following three compounds in order of increasing boiling point.
II. CH3CH2OH III. CH3OCH3
X
< "HL
< H.
Ou^"
u
OU- (
Ci
c-c-c
I
c-c-c-c
c-c-c-c
c
9. Which one of the following gives only one monochlorination product?
L 2,2-dimemylpropane^)
B^2,2-dimethylbutane ~
V 2,3-dimethylbutane
C - Ci - C
c
X, 2-methylpropane
10. Arrange the following alcohols in order of their decreasing reactivity with HBr (most reactive first).
H3C
OH
~ir\
~*
,ott
J^
./\.
OH
f
7*""
.X
./\.
'
'
v_7
c
rv_ — <\
vJ U
rt
>-•
xG*
i
n
Y' 0 in
H
> HI >
c c
11. hidicate the major product of the reaction shown below.
H3CCH2CH3
-H
H-
-H
H-
CH2CH3
<"
B.
-CH3
CH2CH3
C.
Bonus Question: (2 points each answer)
dicate the absolute configuration of C2 in the reactant molecule.
Indicate the absolute configuration of C2 in the product molecule.
12. Complete the following reactions. Draw the structure of the major product of the reaction in each case. If
you have reason to believe no reaction can occur under the conditions described, simply write NO
REACTION.
_
~
,d
I
' acetone-H2O
CH3
(c)
O2N
V
CH2CH2Br
0
il
CH3CONa^
acetic acid
!
\
(d)
CH3CH2Br
1
CH2SNa
(e)
Hp£H2CH2—<.
>-CH2CH2OH
^.
(t)
CH, o
,COCH2CH3
pyridine"
OH
(g)
CH3
CH2CH2CH2CH2OH
HBr
H3C
(h)
O
CH2CH2OH
PBr3
pyridine
(i)
CH3
CH3gH2C—OH
HC1
CH3
G)
Br2, light
100°C *
(monobromination product, indicate structure)
Super Bonus Problem: (10 points for perfect answer)
Indicate all isomers of molecular formula C^g. Mention the systematic name for each isomer. Indicate tl
constitutional and stereoisomers.
>
v
i
\
\v-c-c-c-c-
^
/en^
^-s
-J