Table 3.
| |||||
---|---|---|---|---|---|
entry | substrate | product | yield (%) | ee (%) | mol % 11 |
1b | 16 | 75 | 87 | 15 | |
2 | 18 | 82 | 80 | 20 | |
3c | 20 | 86 | 80 | 15 | |
4c | 22 | 79 | 86 | 20 | |
5c | 26 | 84 | 81 | 20 |
Conditions unless otherwise noted: 1.1 1.2 equiv NBS, 1.1 1.3 equiv BrTi(Oi-Pr)3, 15–20 mol % (R,S)-11, hexanes, −20 °C, 4–12 hours;
3:1 hexanes/CCl4;
absolute configuration unconfirmed.