| Entry | Catalyst | Yield* (%) |
| 1 | None | - |
| 2 | InCl3 | 20 |
| 3 | L-proline | 32 |
| 4 | PTSA | 90 |
| 5 | I2 | 18 |
| 6 | CAN | 62 |
| 7 | FeCl3 | 36 |
| 8 | ZnCl2 | 15 |
| 9 | Silica gel | 10 |