Post on 13-Apr-2018
c) cis-2-hexene
b) 1-ethyl-4-isopropylcyclohexane
a) 2,2-dimethylbutane
d) ethylene
1. Draw the structure of the following compounds. Include all hydrogens in the structure (i.e. CH3CH3 rather than C-C for ethane).
e) (Z)-2-bromo-2-pentene
2. Hydrocarbon X has 50 carbons, 2 π bonds, and one ring. How many hytdrogens are present in a molecule of X ?
3. Complete the following Newman projection for the most stable conformation of octane viewed down the C3-C4 bond.
Answer
5. How many of the four methyl groups in the following structure will be equatorial in the more stable chair conformation?
CH3
CH3
CH3
CH3
4. Complete the wedge-dotted line structure for the following Newman projection:
H
Br
CH3
H
Br
H
H
CH3
H
CH3and
a)
CH3
CH3
HH
H
CH3and
b)
6. Indicate (in the boxes) the isomer relationship between the following pairs. Your only choices are constitutional, configurational, or conformational:
H
CH3
H
CH3
H
CH3CH3
H
CHCH2CH3
Give the formal charge on the indicated atom in the following structures:9.
C
CH3
CH3
Indicate (in the boxes) the acids and the bases in the following acid-base reaction:7.
For the above structure X:
Br
BrX
S OHF
O
O
S OHHO
O
O
S OF
O
O
S OHO
O
O
H
H
+(-)
a)
How many configurations are possible for molecules with the constitution of X?
b)
How many chirality centers are present in the structure of X?
CH3 C
CH3
CH3
CH3a) b)
8.
++
progress of reaction
ener
gy
AB
C
9. For the above energy diagram:
Which product (A, B or C) is formed at the slowest rate?
a)
Answer
Which product (A, B or C) is most stable?b)
Answer
10.
Which one of the above structures (A, B or C) would have (2R, 3R) as its configuration prefix?
a)
c)
Which two of the above structures are related as enantiomers?
Which one is properly termed a ‘meso compound’?
Answer
Answer
AnswerAnswer
+
OH
HO
CH3
CH3
H
H
A B C
b)
d) Which one is an achiral molecule?
Answer
H
H
CH3
CH3
OH
HOOH
H
CH3
CH3
H
HO
11. For the above four structures (A, B, C & D):
A
Which one is (1R, 2S)-1-bromo-2-methylcyclohexane?a)
b) Which one is identical to X (below)?
B C
Answer
Answer
BrBr
D
Br
CH3
BrCH3CH3CH3
X
Which one is the enantiomer of A?c)
e) If C has a specific rotation of (+)20o, which one must have a specific rotation of (-)20o?
Answer
Answer
d) Which two are diastereomers of B?
AnswerAnswer
and
Br
H
CH3
H
f) Which one would be mixed with D to form a racemic mixture?
Answer
A B C
CH312.
Which of the above three carbocations (A, B or C) is the most stable?
Answer
(+)CH2(+)
CH3(+)
H
A B C
CH313.
Which of the above three olefins (A, B or C) releases the least heat upon catalytic hydrogenation to form methylcyclohexane?
Answer
CH3 CH2
Draw the structure of Compound X (C10H16) in the box, based on the following ozonolysis result:
14.
O3
Zn,H3O+
1)
2)
Compound X(C10H16)
CH3C
CH2C
CH3
O O
HC
CC
H
O O
CH3 CH3
+
c)
Draw the structure of the major organic product of the following reactions.15.
16. Draw the structure of the olefin monomer (in the box) used to make the following polymer:
a)BH3
b)
H2SO4
H2O2, NaOH
1)
2)
show stereochemistry
CCH3
CH3
CHCH2CH3H2O,
NaBH4C
CH3
CH3
CHCH2CH3Hg(OAc)2, H2O1)
2)
d)
NMOC
CH3
HC
OsO4H
CH3
show stereochemistry
e)
CCH3
HC
CH3
H
show stereochemistry
+
C
Cl
O OO
H
CO2H
Cl
olefin monomer
CH2 CH CH2 CH CH2 CHROOR
CH3
polymer
Draw appropriate structures in the boxes:17.
a)
CCH3
CH3CHCH2CH3 HBr+
more stable carbocation intermediate major organic product
b)
Br2/H2O+
bromonium ion intermediate, show stereochemistry with wedge/dotted lines
major organic product, show stereochemistry
CH3
c)
initial carbocation
organic product
CH
HCl
1,2 hydride shift
rearranged carbocation
CH2
Cl(-)