Page 21 - Demo-1

Enzymatic Methods - Reductions of β-Ketoesters OHO OHO OH OH OH
H3C
OEt H3C OEt
CO2Et
CO2Et
CO2Et
1 2 OMe3 4 5
OH
CO2Et
O OOH OO OHO
O
MeO
OMe S
Product
1 2 3 4 5 6 7 8 9 10
Microorganism
G. candidum Baker's yeast
M. racemosus Saccharomyces sp. Baker's yeast
K. magna Y. lipolytica
Dipodascus sp. Baker's yeast Baker's yeast
Yield (%)
80 94 75 95 72-85 80
95 80 74 71
de (%)
98 92 98 98 99 100 -
- -
98
ee (%)
98
99
99
98
99
94
95
99
98
85
OH
BocN
CO2Et
6 7 8 9 10
OH
Pellissier, H. Tetrahedron 2003, 59, 8291
Ward, R. S. Tetrahedron: Asymmetry 1995, 6, 1475
Enzymatic Methods - Other Selected Reductions
OH O
OH OH
S
OH
OH
OH
SEt
C5H11
CO2Et
CN
NHBn
OH
MeO
OH OH O CN
OH O
1234
SO2Ph
NH2
5678
Product 1
2
3
4
5
6
7
8
Microorganism
Baker's yeast Baker's yeast Baker's yeast S. montanus Baker's yeast R. arrhizus M. isabellina M. isabellina
Yield (%) de (%) 88 100 82 76 76 -
89 - 95 96 97 98
ee (%) 96 99 80 97 98 99 99 99
72:28 dr 100 92
92
Pellissier, H. Tetrahedron 2003, 59, 8291