Table 2.
Formal retro-[1,3]/[1,3]-dipolar cycloaddition
| ||
|---|---|---|
| Entry | Conditions | Result |
| 1. | 9 + 6, 90 °C sealed tube 1.5 days | 9 + 5 |
| 2. | 9 + 6, 160 °C sealed tube 12 h | 9 + trace 5 |
| 3. | 9 + 6, 190 °C sealed tube 12 h |
9 + 5 1 : 1 |
| 4. | 9 + 6, 220 °C sealed tube 12 h | 28% 5 |