orgo chem homework 3
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CHEM3112.docxName #_______________________________ Grade_________________
1. Using the nomenclature guidelines given in class and the restrictions shown below, provide suitable names for compounds I and II. (3 pts)
2. The IUPAC name for the following compounds: (3 pts)
3. Using cis/trans prefixes as appropriate, give the IUPAC names for the following: (3 pts)
4. Starting with CnH2n+2, derive the general formula for the compounds shown: (3 pts)
5. Determine the degree of unsaturation for the each of the compounds shown below. (3 pts)
(a) C9H11Cl5O2 (b) C10H12Br2N4
6. Using appropriate E/Z prefixes, write the correct IUPAC names for the following compounds: (3 pts)
7. Draw structural formulas for the following compounds: (3 pts)
(a) (2Z,4Z)-2,4-dibromo-3-methylhepta-2,4-diene
(b) ((2E,4Z)-2-bromo-3,5-dichloro-4-methylhexa-2,4-diene
8. Classify the following carbocations as primary, secondary, tertiary, methyl, or vinyl carbocations as applicable: (3 pts)
9. Classify the following compounds as E/Z- structures: (3 pts)
10. Classify each of the following compounds as a cis-trans structure. Write NA if the compound cannot exist be classified as cis or trans. (4 pts)
11. Rank the following alkenes in order of increasing stability (least to most stable): (3 pts)
12. Rank the following carbocations in order of increasing stability: (3 pts)
13. Classify each of the following species as a nucleophile or an electrophile: (4 pts)
14. Rank the following free radicals in order of increasing stability: (3 pts)
15. Rank the following carbanions in order of increasing stability: (3 pts)
16. Which of the following carbocations are likely to rearrange by a 1,2-hydride or a 1,2-methyl shift? (3 pts)
17. Consider the energy diagrams (I, II, and III) for the three different reactions shown below when answer questions 18(a) – (f). Write NA if an applicable answer is not given. (6 pts)
(a) Which diagram if any represents the slower endergonic reaction? __________
(b) Which diagram if any represents the faster endergonic reaction? ___________
(c) Which diagram if any represents the slower exergonic reaction? __________
(d) Which diagram if any represents a faster exergonic reaction? ____________
(e) Which reaction has the lowest activation energy? ___________
(f) Based on the energy diagrams, which reaction leads to the least stable product? _______
(g) Based on the energy diagrams, which reactant is thermodynamically least stable? ______
(h) Based on the energy diagrams, which product is thermodynamically most stable? _______
18. Consider the energy diagram shown below when answer questions 19 (a) – (f). (6 pts)
(a) The rate-determining step for the reaction is______________ (A C, C E, or E G)
(b) The fastest step in this reaction is ___________________ (A C, C E, or E G)
(c) The transition states for this reaction are _________________
(d) This reaction is clearly _______________________________ (exergonic, endergonic)
(e) Which is more stable, intermediate C or product E? _______________________________
(f) Based on the Hammond Postulate, transition state F is more similar in structure to which species, E or G? ______________________
19. Which of the following statements about the following reaction is correct? (3 pts)
(a) Since G > 0, Keq is less than 1, and the reaction favors products.
(b) Since G > 0, Keq is greater than 1, and the reaction favors reactants.
(c) Since G < 0, Keq is less than 1, and the reaction favors reactants.
(d) Since G < 0, Keq is less than 1, and the reaction favors reactants.
(e) Since G < 0, Keq is greater than 1, and the reaction favors products.
20. For each of the following reactions, decide whether entropy is increasing (+S) or decreasing (S). (3 pts)
21. Which of the following reactions is/are consistent with Markovnikov’s rule? (3 pts)
22. Classify each of the following reactions as a substitution, elimination or addition reaction: (3 pts)
23. Give the major organic product(s) for each of the following reactions: (2 pts each product)
24. Give the alkene and the reagent that are best suited to synthesize two of the following compounds: (2 pts each)
25. Calculate Keq for the following reaction at 25 oC. (3 pts)
26. Use the bond dissociation energies provided below to calculate Ho in kcal/mol for the following reaction. Classify the reaction as exothermic or endothermic. (3 pts)
27.
(a) (b)
CH
3
CH
3
CH
3
H
3
CCH
2
CH
3
CH
3
I II
I II
Cl
I II
Cl
+
+
+
+
I
II IIIIV
I
CH
2
C
C
CH
2
CHCH
2
OH
CHCHCH
3
CH
2
II
III
H
2
N
CC
CH
2
CH
CH
2
H
2
N
CC
CH
Br
CH
2
CH
2
CH
2
CH
3
CH
2
HO
NH
2
CH
3
HO
CH
2
CH
3
CH
3
OH
I II III IV
I II III IV
I II III IV
CH
3
CH
2
CH
2
CH
2
CH
3
C
CH
3
CH
2
CH
3
CH
3
CHCHCH
3
I II III IV
CH
3
CCH
3
CH
3
CCH
CH
3
O
C
N
CH
3
CH
3
I II III IV
I II III
I II III
IV
Progress of Reaction
F
r
e
e
E
n
e
r
g
y
Progress of Reaction
F
r
e
e
E
n
e
r
g
y
Progress of Reaction
F
r
e
e
E
n
e
r
g
y
III
III
A
B
A
C
A
D
A
C
D
A
B
A
Progress of Reaction
F
r
e
e
E
n
e
r
g
y
IV
A
E
A
E
F
A
B
C
E
Progress of Reaction
F
r
e
e
E
n
e
r
g
y
D
G
AG
D
C
4
H
2
O
4
2-
+ H
2
O C
4
H
4
O
5
2-
G
o
= 3.25 kJ/mol
_
(a)
CH
3
OCH
3
(g) + H
2
O(g) 2CO(g) + 4H
2
(g)
(c)
2CH
4
(g) + 2CO
2
(g) C
2
H
4
(g) + 2H
2
O(g) + 2CO (g)
(b)CO
2
(g) + 3H
2
(g) CH
3
OH(g) + H
2
O(g)
+ HBr
Br(a)
+ HBr
(b)
Br
+ HBr
(c)
Br
HBr
Br
2
Heat
+(a)
Br
+
(b)
CN
Br
+
Br
CN
+
Br
2
+
(c)
Br
Br
+
H
2
(a)
(b)
2, NaBH
4
1. (CF
3
COO
-
)
2
Hg. CH
3
OH
+
H
2
O
(c)
H
2
SO
4
+H
2
(d)
Pt
+HCl
(e)
H
2
O
2
+
HBr
(f)
H
2
O
2
2. HO
-
, H
2
O
2
, H
2
O
1. BH
3
, THF
(g)
+CH
3
OH
(h)
H
2
SO
4
+
HBr
(i)
+Cl
2
(j)
+
Cl
2
(k)
H
2
O
+
CH
3
OC
O
OH
(l)
Alkene + Reagent
CCH
2
CH
2
CH
3
CH
3
CH
3
Br
(a)
1
2
I (Name as an alkane)
O
Cl
II
Br
Alkene + Reagent(b)
OH
Alkene + Reagent(c)
OH
Alkene + Reagent(d)
Cl
A + B C + D DG = -1.45 kcal/mol
G
o
= - RT LnK
eq
R= 0.001987 kcal/mol.K
ClCl
CHH
+
HCl
+
(CH
3
)
2
CHCl(CH
3
)
2
