Phosphotungstic acid catalyzed regio-selective O-4 ring opening reactions.
Entry | SM | H3[P(W3O10)4] (equiv.) | Product | Yield |
---|---|---|---|---|
1 | 5a | 0.05 | 6a | 31% |
2 | 5a | 0.1 | 6a | 80% |
3 | 5a | 0.2 | 6a | 79% |
4 | 5b | 0.1 | 6b | 82% |
5 | 5c | 0.1 | 6c | 86% |
6 | 5d | 0.1 | 6d | 79% |
7 | 5e | 0.1 | 6e | 69% |
8 | 5f | 0.1 | 6f | 80% |