Problem 26 Chemical Structure and Absolute Stereochemistry of Coniine

1. CH3I (Excess)
H ∆
H H
H 2. Ag2O, H2O + - CH3CH2CH2
CH3CH2CH2 N CH3CH2CH2 N OH N(CH3)2
CH3 CH3
H A

CH2CH2CH3
1. CH3I H
A H ∆ 1,4 -
2. Ag2O, H2O + Me octadiene
CH3CH2CH2 N +
OH- H
Me Me CHCH2CH3
H
CHCH2CH3
1,5-octadiene

H C6H5CH2OCOCl (Z-Cl) KMnO4

ZHN
0 H COOH
CH3CH2CH2 NaOH, 0 C CH3CH2CH2
N
CH3CH2CH2 N ∆ H
H
Z

H2, Pd/C H2N

COOH
CH3CH2CH2
H

(S)- 5-aminooctanoic acid

The KMnO4 oxidation reaction step is based on A. M. Castano, J.M. Cuerva, A. M.
Echavarren, Tetrahedron Letters, 35, 7435-7438 (1994)

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Problem 27: The chemistry and identification of flavonoids
1.
OCH3
1
8 1'
H3CO 3'' O
6'

5 4'' 4

H3CO O
B
OCOCH3
1
8 1'
H3COCO 3'' O
6'

5 4'' 4

H3COCO O
C
2. a) down field. The 1H-NMR resonance of phenolic proton involvement in hydrogen
bonding will be observed at very low magnetic field (~ 12ppm).
3.

OH

HO OH

OH
HO

D E
4. 13C-NMR would be expected to show three characteristic peaks of the three different
carbonyl groups.
OCOCH3
1
8 1'
H3COCO 3'' O
6'

5 4'' 4

H3COCO O
C

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Problem 28: Synthesis of peptides
1
C6H5
H H
N CO2H N CO2H
H2N H2N
O O
C6H5
Dipeptide II
Dipeptide I

C6H5
H H
N CO2H N CO2H
H2N H2N
O O
C6H5
Dipeptide III Dipeptide IV
The cyclic dipeptides (diketo piperazines) must also be considered:
C6H5
C6H5
O O O
HN HN HN
NH O NH NH
O O
C6H5
DP-I DP-II DP-III
2. Best answers are 5 and 2.
3.
O O

N N

4. Benzyl chloroformate, reagent No 4, would react easily with an amine in the

following way:
base
C6H5CH2OCOCl + H2NR C6H5CH2OCONHR + HCl

5. If we assume the intermediate formation of a carbonium ion, the ease of formation

of such ion would parallel its stability. Electron delocalization is most extensive in
case D:
H H
+ H

CH3O
CH3O+ MeO

And least effective in case A:

O CH2 O CH2
N N
O O

In the same way the cation from B is better stabilized than the cation from C.
Therefore, the order of increasing lability is: A<C<B<D.

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Problem 29: Oleuropein hydrolysis
1.
COOCH3 COOCH3
O O
R R
O O O
O

O O

O O
OH OH
HO HO

OH OH
OH OH

(a) (b)
2. 3.
OH
OH
HO HO Hd

a b
OH He CH2 CH2 OH
Hc
The correct structure is C

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 Problem 30: Stereochemistry of the Addition Reactions to Alkenes

CH3 CH3
H H
H Br Br H
a) C C
(R) Br H H Br
Br C CH3
H Br H Br
H CH3
CH3 CH3
No Yes

CH3 CH3
H 3C H
H Br H Br
b) C C
(S)
H Br Br H
H C Br
H3C H H Br Br H

CH3 CH3

No Yes

CH3 CH3

H Br H Br H
Br Br CH3
H3C H Br Br H
C (R) C H
(S)
c) C C Br H H Br
H H Br H Br H
CH3 CH3

Yes Yes

CH3 CH3
H Br
H Br H Br
H3C C (R) H
H Br Br H
d) C C
(S)
H C Br H Br Br H

H3C H H Br H Br

CH3 CH3

No No

64
Problem 31: Identification of Organic Compounds

CH3
C
C CH2CH2CH3
H
H2/Pd/C

CH3 CH3
(A)

H2/Lindlar

CH3
CH
CH COOH COOH
H H COOH H COOH
O3 I2/NaOH
CH3 OH
KMnO4 -CHI3
CH3 O O

(B) (C)
Problem 32: Lipases
a)
O O O O O O

C CH3 CH C CH2Cl C CCl3 C CF3 C CF2CF3

(6) (5) (4) (3) (2) (1)
b)
O

HN H

O O O

c)

CH3CO2CH3 CH3CO2CH2CH3 CH3CO2CH2 CH3CO2C(CH3)3

(1) (2) (3) (4)

65