Table 1.
| |||
---|---|---|---|
Entry | Acid | Equivalents | Yield % |
1 | None | N.A. | NR |
2 | HCl | 1.0 | 50 |
3 | Amberlyst-15 | 1.0 | NR |
4 | HBF4•OEt2 | 1.0 | 86 |
5 | Tf2NH | 1.1 | 46 |
6 | TfOH | 1.1 | 62 |
7 | TfOH | 0.3 | 42 |
8 | 2 | 1.1 | 96 |
9 | Sc(OTf)3 | 0.1 | 34 |
| |||
---|---|---|---|
Entry | Acid | Equivalents | Yield % |
1 | None | N.A. | NR |
2 | HCl | 1.0 | 50 |
3 | Amberlyst-15 | 1.0 | NR |
4 | HBF4•OEt2 | 1.0 | 86 |
5 | Tf2NH | 1.1 | 46 |
6 | TfOH | 1.1 | 62 |
7 | TfOH | 0.3 | 42 |
8 | 2 | 1.1 | 96 |
9 | Sc(OTf)3 | 0.1 | 34 |