Table 1.
Optimization studies of epoxide opening/cyclization sequence using batch MW.
 | ||||||
|---|---|---|---|---|---|---|
| Entry | Temp (°C) | Time (min) | Base (equiv.) | Epox (equiv.) | % Con. (Yield) | Prod. |
| 1a | 125 | 3 | tBuOK (3) | 1 | Decomp. | 2 |
| 2a | 110 | 3 | tBuOK (2) | 1 | 5 | 2 |
| 3a | 110 | 5 | tBuOK (1.5) | 1 | 30 | 2 |
| 4a | 110 | 20 | tBuOK (1.5) | 1.2 | 54 | 2 |
| 5a | 180 | 1 | tBuOK (1.5) | 1.2 | 61 | 2 |
| 6a | 180 | 1 | tBuOK (1.5) | 2 | 78 | 2 |
| 7a | 180 | 1 | tBuOK (1.5) | 3 | 100 (70) | 2 |
|
| ||||||
| 8b | 125 | 1 | DBU (1.5) | 3 | 25 | 3 |
| 9b | 150 | 1 | DBU (1.5) | 3 | 60 | 3 |
| 10b | 180 | 1 | DBU (1.5) | 3 | 100 (90) | 3 |
| 11b | RT | 72 h | DBU (1.5) | 3 | 26 | 3 |
[a]
Compound 2 generated with 2-ethyloxirane;
[b]
Compound 3 generated with 2-(butoxymethyl) oxirane.