ALKYL HALIDE PROBLEMS
1. Circle the substrate that will react faster with NH3 by SN2. Do not guess. One mark will be subtracted for each incorrect answer.
a)
b)
2. Circle the reagent that will react faster under the stated conditions. Do not guess. Wrong answers will be subtracted from correct answers.
a) (CH3)2CH-Br or (CH3)2CH-Cl in an SN1 reaction
b) CH3CH2-Cl in methanol or CH3CH2-Cl in acetone in an SN2 reaction
c) (CH3)3Br or CH3-Br with NO3-
d) C6H5-Br or CH2=CH-CH2-Br with I-
3. What is the rate effect of the following conditions on the reaction shown below. There are 2 parts to the answer. State whether the reaction will proceed faster, slower, or no change. Then state the factor by which it changes, e.g.,1´ (unchanged), 2´, 3´, etc.
a) The concentration of NaNO3 is doubled while the concentration of substrate is tripled.
b) The concentration of NaHS is halved while the concentration of substrate is doubled.
c) The concentrations of both substrate and nucleophile are tripled.
4. Circle the better nucleophile and explain why it is better. Do not guess as 1 mark will be subtracted for each incorrect answer.
a)
b)
5. Number the following substrates in order of SN1 reactivity, i.e., 1 = fastest, 4 = slowest
a)
b)
6. Draw and give the common names of the four isomers of butyl bromide. Then number them in order of SN2 reactivity (1= fastest, 4 = slowest).
7. Name 3 solvents that favor SN1 reactions over SN2 reactions.
8. Name 3 solvents that favor SN2 reactions over SN1 reactions.
9. Draw the structures of the reactant and product in the following reaction. Also name the product and name the reaction type and show the reaction mechanism.
2-bromobutane + KI ®
10. Draw the structures of all major products of the following reactions
a)
b)
c)
d)
e)
11. Draw the major products of the following reaction. Then state the type of mechanism, i.e., SN1, SN2, E1, or E2. Show the mechanism and name the product(s).
12. Write the structures of the main products of the following reactions and state the reaction mechanism, e.g., SN1, SN2, E1, or E2
a) (CH3)2CH-Br + Na+ CH3COO- ®
b) (CH3)2CH-Br + CH3COOH ®
c) (CH3)2CH-Br + (CH3)3CO- Na+ ®
d) CH3CºC- Na+ + CH3-CHBr-CH3 ®
e) CH3CH2CH2Br + C2H5O- Na+ ®
13. Draw the structures of the products formed when trans-1-bromo-2-methylcyclopentane reacts with the following reagents. State the type of reaction mechanism
a) KOH
b) C2H5OH
c) KI
14. Name the mechanism. Show the complete mechanism for the following reactions.
Name the product(s) formed.
a) t-butyl alcohol + HBr
b) iodocyclopentane + KOH
15. Write the formulas or draw the structures of 1 set of reagents that could be used to form each of the following products in good yield by a substitution or elimination reaction.
Also state the type of reaction mechanism you chose, i.e., SN1, SN2, E1, or E2
a)
b) (CH3)3C-Br ¬
c) (CH3)2C=CH2 ¬
d) CH3CºCCH(CH3)2 ¬
16. Write equations and draw structures to show how the alkyne shown below can be produced from a terminal alkyne in 2 steps. Show the mechanisms by pushing electrons and name the types of reactions.
17. Write equations to show how the following products can be synthesized using a substitution reaction at some point. There are marks for the reagents used; so list them all. No marks are assigned for mechanisms.
a)
b)
c)
18. Write equations showing how the following conversion is carried out. The starting material is your only source of carbon. Hint: use some of it to make a Gilman’s reagent. List all reagents and all intermediate products if more than one step is required. Mechanisms are not required.
19. Draw the full mechanism for the reaction of chlorocyclohexane + methanol upon heating. If more than one reaction occurs, draw both mechanisms and show both sets of products. Identify the type of mechanism(s) as SN1, SN2, E1, or E2.
20. Draw the structures and name the products of the following reactions:
a)
b)
c)
d)
e)
21. Write equations showing how the following conversions are carried out. List all reagents and all intermediate products if more than one step is required. Mechanisms are not required
a)
b)
c)
d)
e)
f)
g)
h)
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