Quiz 1 - Chemistry at Caltech

Ch#41c,#Organic#Chemistry#
Quiz#1#
Question 1
_____/12 points
Question 2
_____/08 points
Question 3
_____/16 points
Question 4
_____/16 points
Question 5
_____/16 points
Question 6
_____/16 points
Question 7
_____/16 points
TOTAL
_____/100 points
Name (printed)
Signature
There are six pages (2–7) of questions in this exam.
There is a periodic table on page 8.
1 of 8
April#23,#2014
(1) (3 points each, 12 points total) Please provide:
(1) the ML aXb assignment (i.e., give a and b) ________
Cl
PPh 3
(2) the formal oxidation state of the metal ________
CO
(3) the dn electron count (i.e., give n) ________
Ir
Ph 3P
(4) the total electron count ________
(2) (4 points each, 8 points total) Please provide the product of the illustrated reactions.
Ph
I
cat. Pd(PPh 3)4
cat.
Cl
PCy 3
Cl
Ru
CH2
PCy 3
2 of 8
(3) (16 points) Please provide the best stepwise mechanism for the illustrated transformation, including the
name of each elementary step (e.g., ligand substitution, oxidative addition, reductive elimination, β-migratory
insertion, β-elimination, α-migratory insertion, four-center reaction, or [2+2] reaction).
Me
H H
CO
O
HCo(CO) 4
H
Me
H
3 of 8
(4) (4 points each, 16 points total) Please provide the product of the illustrated reactions. If no reaction is
expected, write "NR".
O
Me
H
OMe
O
Me
NaBH 4
NMe 2
O
Me
H
Me
O
Me
EtOH (solvent)
EtOH (solvent)
SOCl2
OH
4 of 8
(5) (16 points). An amide hydrolysis performed under basic conditions in labeled water was stopped before
the reaction was complete. The "unreacted" amide contained mostly labeled oxygen in the carbonyl oxygen.
Please provide the best explanation for this observation, including a mechanism for the formation of the
labeled amide (with all arrow pushing).
O
Me
HO
NMe 2
(1 equivalent)
H 2O
O
Me
5 of 8
+ carboxylate
NMe 2
(6) (16 points) A hemiaminal ether can be converted into a ketone upon treatment with aqueous acid. Please
provide the best mechanism for this process, including all arrow-pushing
O
Me
NMe
Me
H
(1 equivalent)
H 2O
O
HO
Me
a hemiaminal ether
6 of 8
Me
NH 2Me
(7) (16 points total) In the Negishi reaction illustrated below, in addition to the formation of the desired
product (PhCD 2CD 3), some Ph–D (an undesired side product) was isolated at the end of the reaction,
Please provide the best stepwise mechanism for the formation of Ph–D.
Ph
I
BrZn CD2CD 3
cat. Pd(PPh 3)4
7 of 8
Ph CD2CD 3
Ph D
18
1
13
2
3
132.90
137..33
(223)
(226)
8 of 8
14
15
16
17