Chemistry Reference
In-Depth Information
17.19
First protect the amino group of the C-terminal amino acid (Phe) as described in
eq. 17.15:
H
O
H
O
[
(CH
3
)
3
CO
]
C
O
2
+
O
-
H
3
N
C
C
NH
C
C
OH
base
CH
2
C
6
H
5
CH
2
C
6
H
5
O
=
C
OC
(CH
3
)
3
Next attach the N-protected phenylalanine to the chloromethylated polystyrene:
H
O
-
CH
2
Cl
+
NH
C
C
O
CH
2
C
6
H
5
H
O
NH
C
C
O
CH
2
CH
2
C
6
H
5
polystyrene
backbone
Then deprotect the amino group of the Phe:
H
O
CF
3
CO
2
H
NH
C
C
O
CH
2
CH
2
Cl
2
CH
2
C
6
H
5
H
O
H
2
N
C
C
OCH
2
CH
2
C
6
H
5
Next couple the polymer bound phenylalanine with N-protected alanine (Ala):
H
O
H
O
NH
C
C
O
H+
H
2
N
C
C
OCH
2
CH
3
CH
2
C
6
H
5
DCC
H
O
H
O
NH
C
C
N
H
C
C
OCH
2
CH
3
CH
2
C
6
H
5
