Chemistry Reference
In-Depth Information
Table 9.2
Asymmetric hydroformylation of 2,3-dihydrofuran 34 with carbohydrate ligands.
catalyst (0.25 mol%): Rh(acac)(CO) 2 /ligand* (ratio 1:2)
H 2 , CO, toluene
CHO
*
+
*
CHO
O
O
O
34
32
33
(undesired)
R 2
R 1
O
O
O
Entry
Ligand
Yield 32 + 33 (%)
Ratio 32 : 33
ee (%)
=
O
R 2
R 1
D- xylo
O
O
O
P
P
O
O
O
O
4b
1
88
78 : 22
48 (R)
R 1
=
R 2
=
t Bu
O
O
Me
Me
12a
2
80
75 : 25
<
5
R 1
=
R 2
=
H
D- gluco
O
12b
Me
O
3
O
100
76 : 24
75 (R)
P
P
O
O
R 1
=
R 2
=
t Bu
O
O
12c
4
100
74 : 26
49 (R)
O
R 1
=
t Bu, R 2
=
OMe
O
Me
12d
Me
5
100
73 : 27
61 (R)
R 1
=
TMS, R 2
=
H
L- ido
O
P
Me
O
O
O
13b
O
6
O
92
69 : 31
21 (S)
P
O
R 1
=
R 2
=
t Bu
O
O
Me
Me
( Continued )
 
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