Table 5.
entry | conditions | yield, %a |
erb | |
---|---|---|---|---|
1 | (S)-BINOL (24 mol %) Ti(Oi-Pr)4 (20 mol %) −78 to −20 °C |
30 | 99:1 | |
2 | (+)-Ipc2B-Cl (1 equiv) −78 °C |
70 | 90:10 | |
3 | (+)- Ipc2B-OMe (1 equiv) −78 °C |
73 | 96:4 | |
4 | (+)- Ipc2B-OMe (1 equiv) −100 °C |
71 | 96:4 | |
5 | (R,R)-65 (10 mol %) i-Pr2NEt / CH2Cl2 −78 °C |
76 | 95:5 |
Yield corresponds to isolated product.
The enantiomeric ratio was determined by CSP-SFC.