Problems 787
- In order to solve this problem, you must read the description of the Hammett treatment given in Chapter 17, Problem 76.
When the rate constants for the hydrolysis of several morpholine enamines of para-substituted propiophenones are determined at
the value is positive; however, when the rates of hydrolysis are determined at the value is negative.
a. What is the rate-determining step of the hydrolysis reaction when it is carried out in a basic solution?
b. What is the rate-determining step of the reaction when it is carried out in an acidic solution?
- Propose a mechanism for each of the following reactions:
a.
b.
c.
d. CH 3 CH CHCCH 3 ++
+
CH 3
CHCH 2 CCH 3
HH
O O
O
N
N
- HCl, H 2 O
+ CH 3 CH 2 SH
OH
SCH 2 CH 3
OH
O
O
HCl
H 2 O
O
(HOCH 2 CH 2 CH 2 ) 2 CHCH
O
O
C
CH 3
OCH 3
Br
CCH 3
O
HCl
H 2 O
σ
= 1.39 (pH = 4.7)
= −1.29 (pH = 10.4)
− 20 + 2 + 4
log
kobsd
(s
−^1
)
a morpholine enamine of
a para-substituted propiophenone
CC
H
Z
CH 3
N
O
pH=4.7, r pH=10.4, r
s, r
