Chemistry Reference
In-Depth Information
Table 4.6
Diels-Alder reactions of modified carbohydrate dienes β - 126 with cyclic dienophiles.
R 4
R 3
D-gluco
O
R 4
R 4
O
O
R 2
H
H
O
R 3
R 3
+
O
benzene
OAc
+
R 1
R 2
R 2
R 1
R 1
AcO
O
b
- 126
O
O
O
O
OAc
AcO
β -D-gluco
β -D-gluco
Entry
Dienophile
Diene
Major product
dr (major/minor)
raw product
Isolated yield
(major
product) (%)
R 1
=
H
O
1
> 99 : 1
69
O
H
a
OTMS
R 1 = CO 2 Et
b
2
>
99 : 1
72
CH 3
R 1
R 1
OTMS
O
O
O
β
-D-gluco
R 1 = Ac
c
3
Not given
65
122
CH 3
127
O
O
β
-D-gluco
H
OTMS
β
-126a
Ph
N
4
95 : 5
87
CH 3
H
O
O
b-D-gluco
128
O
H
Ph
N
5
86 : 14
59
O
H
β
-D-gluco
O
O
b-D-gluco
β
-126b
129
CH 3
O
H
O
CH 3
Ph
N
6
Ph
N
88 : 12
60
O
H
O
β
-D-gluco
O
b-D-gluco
O
β
-126c
130
124a
CH 3
O
H
CH 3
Ph
N
CH 3
7
95 : 5
68
CH 3
O
H
O
β
-D-gluco
O
b-D-gluco
β
-126d
131
OAc
OAc
O
H
OTBS
OTBS
Ph
N
8
89 : 11
59
H
O
O
O
b-D-gluco
β -D-gluco
132
β
-126e
 
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