Kayla Hodge
Extended Exam 3 FS 2020
1.
Which of the following is true for the reaction of 1-bromo-2-methylcyclohexane with Mg and ether
followed by a second and third step of butanone and acidic water respectively?
a. The product is an alkane with 4 possible stereoisomers.
b. The product is an alkane with 8 possible stereoisomers.
c. The product is an alcohol with 4 possible stereoisomers.
d. The product is an alcohol with 8 possible stereoisomers.
2.
The correct name for the molecule below is:
OH
a.
b.
c.
d.
(4R)-4-ethyl-3-pentanol
(4S)-4-ethyl-3-pentanol
(4R)-4-methyl-3-hexanol
(4S)-4-methyl-3-hexanol
3.
Which of the following is not true about acidity?
a. Generally, the more resonance structures a molecule has, the more acidic it is.
b. For any acid, HX, where X is any halogen, acidity trends the opposite as electronegativity.
c. For any carboxylic acid, CH3CH2XCO2H, where X is any halogen, acidity trends the same as
electronegativity.
d. By solvent effects, water is more acidic than methanol, which is more acidic than ethanol.
4.
Which of the following correctly explains periodic table trends?
a. Acidity and bond length correlate while electronegativity does not.
b. Bond length and electronegativity correlate while acidity does not.
c. Acidity and electronegativity correlate while bond length does not.
d. None of these correlate.
5.
Which of the following is false concerning Williamson ether synthesis?
a. The steps are deprotonation followed by an SN2 reaction.
b. It involves an alkoxide ion and a primary, secondary, or tertiary alkyl halide.
c. The product is always an ether.
d. The release of hydrogen gas drives the equilibrium toward the products.
6.
Which of the following terms does not belong?
a. Second-order reaction
b. Carbocation intermediate
c. Substrate and nucleophile dependent rate
d. Charged nucleophile
7.
Which of the following best explains why inversion is preferred in an S N2 reaction?
a. Carbocation intermediate
b. Inductive effects
c. Orbital overlap
d. None of these
8.
Which of the following is not a true statement concerning reaction rates?
a. Increasing the concentration of the nucleophile will increase the rate of E2 and S N2 reactions.
b. Decreasing the concentration of the nucleophile will decrease the rate of an S N2 reaction but not an E2
reaction.
c. Increasing the concentration of the nucleophile will have no effect on the unimolecular reactions of
substitution and elimination.
d. All of these are true.
9.
Which of the following is a true statement?
a. Unlike a leaving group that is attached to an allylic carbon, a leaving group attached to a vinylic
carbon will undergo substitution.
b. The rate determining step of an SN1 reaction is the addition of the nucleophile.
c. ∆G≠ is the difference in energy between the starting material and the transition state in a reaction.
d. In an exergonic reaction, the reactants are more stable than the products.
10. Which of the following is true concerning substitution and elimination reactions?
a. There is never an instance where a reaction between any substrate and nucleophile will lead to an E1
only reaction.
b. Only SN2 reactions undergo inversion; SN1, E1, and E2 do not.
c. A methyl carbon reacted with a charged nucleophile can only undergo Sn2 and E2 reactions.
d. None of these are true.
11. Which of the following is a true statement?
a. The intermediate states of E2 and SN2 have a partial positive charge on the carbon attached to the
leaving group.
b. Elimination reactions may compete with one another depending on the nucleophile of the reaction.
c. Tertiary carbons under E2 reactions will always lead to the Hofmann as a major product.
d. The reverse mechanism of an SN2 is endergonic.
12. Which of the following is a characteristic shared by E1 and E2 reactions?
a. Possibility of hydride shifts
b. Anti-elimination
c. Saytzeff as most stable product
d. Substitution at R of R-L
13. The figure following depicts a Newman projection of a butane with a leaving group.
H
LG
For the molecule to proceed through an E2 reaction, its Newman projection must be:
a. rotated 60 degrees.
b. rotated 120 degrees.
c. rotated 180 degrees.
d. It is fine as is.
14. Which statement is true for the following molecule under SN1 and E1 conditions?
F
a.
b.
c.
d.
There is one substitution product with two chiral centers and two elimination products.
There are a total of 4 elimination products where the major product is one with no E/Z isomerism.
There are two substitution products and three elimination products where only one has E/Z isomerism.
There is only one product from the substitution reaction and one product from the elimination reaction
having no E/Z isomerism.
15. Which statement is true for the following molecule under SN2 and E2 conditions?
F
a.
b.
c.
d.
There is one substitution product with two chiral centers and two elimination products.
There are a total of 4 elimination products where the major product is one with no E/Z isomerism.
There are two substitution products and three elimination products where only one has E/Z isomerism.
There is only one product from the substitution reaction and one product from the elimination reaction
having no E/Z isomerism.
16. For the reaction of the molecule below with propanol:
F
a.
b.
c.
d.
There are 5 elimination products, all but one having E/Z isomerism.
There are 3 elimination products with the major product having E/Z isomerism.
There are 3 elimination products where the Hofmann product is major.
There are 2 elimination products with the minor product having no E/Z isomerism.
17. How many products will occur with the molecule below and H-X?
H2N
CO 2H
a.
b.
c.
d.
1
2
3
4
For the following questions, decide what reactions may occur based on what is given.
The options are:
A. SN1, E1
B. SN2, E2
C. SN1, SN2, E1
D. SN1, E1, SN2, E2
18.
Cl
Answer choice:
19.
NH 3
Answer choice:
20.
NaCN
NH 3
Answer choice:
21.
NaOCH3
HOCH3
Cl
Answer choice:
22.
Br
K O
HO
Answer choice:
E. SN2, SN1
F. SN2 ONLY
G. E2 ONLY
For the following pathway, each arrow represents one step (meaning no steps are compounded). Use the figure to
answer the questions below.
B
2,3-dimethyl-1-pentene
E
D
C
A
Br
G
H
J
Cl
L
I
K
23. Which reaction corresponds to letter A?
a. 1. BH3, THF / 2. H2O2, NaOH
b. 1. Hg(OAc)2, H2O / 2. NaBH4, NaOH
c. 1. H2SO4 (cat), H2O
d. H-Br
24. Which reaction corresponds to letter G?
a. 1. BH3, THF / 2. H2O2, NaOH
b. 1. Hg(OAc)2, H2O / 2. NaBH4, NaOH
c. 1. H2SO4 (cat), H2O
d. H-Br
25. Which of the following is not a possible reagent for step C?
a. PBr3
b. SOCl2
c. HBr
d. Mg, ether
26. How many possible stereoisomers are there for product L?
a. 2
b. 4
c. 8
d. 16
e. 32
F