Problems 181
- a. What product is obtained from the reaction of HCl with 1-butene? With 2-butene?
b. Which of the two reactions has the greater free energy of activation?
c. Which of the two alkenes reacts more rapidly with HCl?
d. Which compound reacts more rapidly with HCl, (Z)-2-butene or (E)-2-butene?
- a. How many alkenes could you treat with in order to prepare methylcyclopentane?
b. Which of the alkenes is the most stable?
c. Which of the alkenes has the smallest heat of hydrogenation?
- a. Propose a mechanism for the following reaction:
b. Is the initially formed carbocation primary, secondary, or tertiary?
c. Is the rearranged carbocation primary, secondary, or tertiary?
d. Why does the rearrangement occur?
- When the following compound is hydrated in the presence of acid, the unreacted alkene is found to have retained the deuterium
atoms:
What does the preceding statement tell you about the mechanism of hydration?
- Propose a mechanism for each of the following reactions:
a.
b.
c.
- a. Dichlorocarbene can be generated by heating chloroform with Propose a mechanism for the reaction.
b. Dichlorocarbene can also be generated by heating sodium trichloroacetate. Propose a mechanism for the reaction.
Cl 2 C
sodium trichloroacetate
Cl 3 CCO− Na+ + CO 2 + Na+ Cl−
∆
O
+ HO−
chloroform dichlorocarbene
CHCl 3 + H 2 O
∆
Cl 2 C + Cl−
HO-.
CCl 3
+ HCCl 3
peroxide
CH 2 CH 3
CH 3
CH 2 + CH 2
H 3 C
N
CH 3 CH 2 CNN+− N
H 2 O
HO CH 3
CH 3
H 3 CCHCH 2
+
H 2 SO 4
CH CD 2
CH 2
CH 3
Br CH 3
CH 3
C
HBr
CH 3 CH 3
Br
+ +
H 2 >Pt
