Download CHEM 2411 – Organic Chemistry I Chapter 3: Additional Problems 1

CHEM 2411 – Organic Chemistry I
Chapter 3: Additional Problems
1) (McMurry 3.12) Give IUPAC names for the following compounds:
a. The 3 isomers of C5H12.
b.
n-pentane
3,4-dimethylhexane
isopentane (2-methylbutane)
neopentane (2,2-dimethylpropane)
c.
d.
CH3
(CH3)3 C CH2 CH2 CH
(CH3)2 CH CH2 CH (CH3)2
2,4-dimethylpentane
CH2 CH3
2,2,5-trimethylheptane
2) (McMurry 3.13) Draw structures corresponding to the following IUPAC name:
a. 3,4-Dimethylnonane
b. 3-Ethyl-4,4-dimethylheptane
c. 2,2-Dimethyl-4-propyloctane
d. 2,2,4-Trimethylpentane
3) (McMurray 3.16) Give IUPAC names for the following cycloalkanes:
a.
b.
1,4-dimethylcyclohexane
1-methyl-3-propylcyclopentane
c.
d.
Br
3-cyclobutylpentane
1-bromo-4-ethylcyclodecane
e.
f.
Br
1-isopropyl-2-methylcyclohexan
4-bromo-1-tert-butyl-2-methylcycloheptane
4) (McMurray 3.17) Draw structures corresponding to the following IUPAC names:
a. 1,1-Dimethylcyclooctane
b. 3-Cyclobutylhexane
c. 1,2-Dichlorocyclopentane
d. 1,3-Dibromo-5-methylcyclohexane
Br
Cl
Cl
Br
5) (McMurry 3.18) Name the following substances, specifying each as cis or trans:
a.
b.
CH3
H
Cl
H
Trans-1-chloro-4-methylcyclohexane
H3C
H
H
CH3
cis-1-ethyl-3-methylcycloheptane
6) (McMurry 3.19) Draw the structures of the following molecules:
a) trans-1-Bromo-3-methylcyclohexane
Br
H
H
b) cis-1,2-Dimethylcyclopentane
H
CH3
H
CH3
c) trans-1-tert-Butyl-2-ethylcyclohexane
H
H
7) (McMurry 3.29) Draw as many compounds as you can that fit the following descriptions:
a) Alcohols with formula C4H10O
OH
OH
b) Amines with formula C5H13N
NH2
NH2
N
H
NH2
N
N
H
N
c) Ketones with formula C5H10O
O
O
O
d) Aldehydes with formula C5H10O
H
O
H
H
O
H
O
O
e) Esters with formula C4H8O2
O
O
O
O
f) Ethers with formula C4H10O
O
O
8) (McMurry 3.34) Draw structures for the following:
a) 2-Methylheptane
b) 4-Ethyl-2,2-dimethylhexane
O
c) 4-Ethyl-3,4-dimethyloctane
d) 2,4,4-Trimethylheptane
e) 3,3-Diethyl-2,5-dimethylnonane
f) 4-Isopropyl-3-methylheptane
9) (McMurry 3.40) Give IUPAC names for the following compounds:
a.
b.
2-methylpentane
2,2-dimethylbutane
c.
d.
2,3,3-trimethylhexane
5-ethyl-2-methylheptane
e.
f.
3,3,5-trimethyloctane
2,2,3,3-tetramethylhexane
g.
5-ethyl-3,5-dimethyloctane
10) (McMurry 3.42) Explain why each of the following names is incorrect:
The best way to answer these questions is to draw the structure as named, to see why it is
incorrect
a) 2,2-Dimethyl-6-ethylheptane
2,2,6-trimethyloctane
b) 4-Ethyl-5,5-dimethylpentane
3-ethyl-2-methylhexane
c) 3-Ethyl-4,4-dimethylhexane
4-ethyl-2,2-dimethylhexane
d) 5,5,6-Trimethyloctane
3,4,4-trimethyloctane
e) 2-Isopropyl-4-methylheptane
2,3,5-trimethyloctane
f) cis-1,5-Dimethylcyclohexane
H3C
H
CH3
H
cis-1,3-dimethylcyclohexane
11) (McMurry 3.44) Give IUPAC names for the following compounds:
a.
b.
H3C
d.
c.
H3C
H
CH3
H
CH3
H
CH3
H
e.
H3C
CH3
CH3
CH3
CH3
H3C
a. methylcycloheptane
b. cis-1,3-dimethylcyclopentane
c. trans-1,2-dimethylcyclohexane
d. trans-1-isopropyl-2-methylcyclobutane
e. 1,1,4-trimethylcyclohexane
12) (McMurry 4.27) Construct a qualitative potential-energy diagram for rotation about the C-C
bond of 1,2-dibromoethane. Which conformation would you expect to be more stable? Label
the anti and gauche conformations of 1,2-dibromoethane.
13) (McMurry 4.31) Draw the most stable conformation of 1,4-dichlorobutane, using wedges
and dashes to represent bonds coming out of the paper and going behind the paper,
respectively.
14) (McMurry 4.32) Draw a chair cyclohexane ring and label all positions as axial or equatorial.
15) (McMurry 4.33) Why is a 1,3-cis disubstituted cyclohexane more stable than its trans
isomer?
16) (McMurry 4.35) Which is more stable, a 1,4-trans disubstituted cyclohexane or its cis
isomer?