Biomedical Engineering Reference
In-Depth Information
Boc
OH
N
Boc
O
Ph
SO
2
Ph
N
O
51b
(10 mol%)
OMe
+
Ph
50% K
2
CO
3
aq
Toluene/TBME/CH
2
Cl
2
-42°C, 16 h
86%
O
O
O
OMe
MeO
OMe
(ee = 91%)
_
Cl
OMe
+
H
NO
2
N
O
N
t
-Bu
O
51b
SCHEME 7.27
O
O
(
S
)-
45
(3 mol%)
CO
2
t
-Bu
CO
2
t
-Bu
Boc
N
+
N
Boc
K
2
HPO
4
Toluene
-20°C, 14 h
99%
N
NH
Boc
Boc
(ee = 91%)
O
(
S
)-
45
(3 mol%)
O
CO
2
t
-Bu
+
Boc
Boc
N
Boc
CO
2
t
-Bu
N
N
N
Boc
K
2
HPO
4
Toluene
-20°C, 40 h
99%
N
NH
O
Boc
Boc
O
(ee = 92%)
Ar
-
Br
CF
3
+
Bu
Bu
P
Ar =
CF
3
Ar
(
S
)-
45
SCHEME 7.28
offers a valuable method for preparing a key intermediate for the asymmetric
synthesis of the aldose reductase inhibitor AS-3201 (ranirestat) [71].
7.9.
FLUORINATION
Organic molecules containing fluorine atoms have attracted much attention because
they often show characters different from the parent compounds due to the unique
properties of the carbon-fluorine bond. Replacement of a hydrogen atom in bioactive
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