CHM 235R Dr. Hascall Spring 2011 Recitation Week 9
3/13/13
1. Give the products of these substitution reactions:
(a)
CH3I + NaOCH3 →
(b)
CH3CH2CH2Br + NaCN →
(c)
(CH3)3CBr + H2O →
2. What reagents would you need to do the following reactions?
(a)
CH3CH2CH2Br → CH3CH2CH2OH
(b)
(CH3)3CBr → CH2=C(CH3)2
(c)
CH3CH2CH2Br → CH3CH2CH2SCH3
3. What is the relative stability of these carbocations?
4. Give the products of these reactions, including their stereochemistry.
(a)
Cl
H
H3C
+ OH– (SN2)
C
CH2CH3
(b)
H3C
Br
+ OH– (SN2)
(c)
+ H2O
Br
5. Rank these nucleophiles in order of increasing strength for SN2 reactions in
DMF:
(a)
H2O
OH–
CH3CO2–
(b)
F–
Cl–
Br–
I–
6. What type of reaction is each of these? In each case, draw the mechanism:
(a)
CH3
H3C
C
CH3
(b)
CH3
CH3OH
Cl
H3C
C
OCH3
+ HCl
CH3
CH3CH2CH2Br + CN– → CH3CH2CH2CN + Br–
7. Sketch a reaction coordinate diagram for a two-step exergonic reaction, in
which the first step is rate-determining. Indicate the locations of any transition
state(s) and intermediate(s), as well as ∆Grxn and the activation energy (∆G‡).