Name ________________________________ ________________________ ________
1a. Rank the molecules below in order of decreasing pK a (increasing acidity) of the indicated H: (2 points) points)
H H H H B
A
pKa
>
C
D
C
>
D
A
least acidic
>
B
most acidic
1b. Rank the following fo llowing in order of reactivity with Br 2 in the presence of FeBr 3. (2 (2 points) points)
O
S
A
Br
B
A
>
D
C
D
>
most reactive
C
>
B
least reactive
2
Name ________________________________
2a. Rank the following species by carbocation stability: (2 points)
A
B
B
C
A
C
least stable
most stable
2b. Rank the following species by carbocation stability: (2 points)
H H3C
CH3 H
A
H3C
CH3
H3C
B
A
H
OH CH3
C
B
D
least stable
H3C
CH3
D
C
most stable
3
Name ________________________________
3. Provide a mechanistic pathway for the biosynthesis of !-terpineol from geranyl pyrophosphate. (5 points)
OPP OH
geranyl pyrophosphate !
OPP
-terpineol
OPP
geranyl pyrophosphate
OPP
PPO CH2
CH2
CH2
internal rotation
PPO
CH2
CH2
CH2 OPP OH H2O
-terpineol
!
4
Name ________________________________ 4. Predict the products of the following Diels-Alder reactions. Show stereochemistry when appropriate. (8 points)
O H
Heat a.
H
H
O O
O
N
C
O
H Heat
c.
N
H C
H O
d.
O
H
Heat
b.
Heat ~OR~
5
H
H
O
Name ________________________________
5. Over the arrows below, write in the reagents needed to produce the following reactions in good yield. If more than one step is needed, number each step 1), 2), etc. (6 points)
