Abstract
The regiochemistry of nitrone cycloadditions has been reexamined. Certain nitrones afford regioisomeric mixtures of isoxazolidines, with a tendency toward increasing amounts of the 4-substituted regioisomer as the ionization potential of the dipolarophile is increased.
| Original language | English |
|---|---|
| Pages (from-to) | 4167-4170 |
| Number of pages | 4 |
| Journal | Tetrahedron Letters |
| Volume | 20 |
| Issue number | 43 |
| DOIs | |
| State | Published - 1979 |
| Externally published | Yes |
Bibliographical note
Funding Information:ppm (protons at C-3 and C-4) characteristic of other S-substituted isoxazolidines derived from this nitrone." Thus it is clear that substitution of the carbon of the nitrone functionality increases the tendency toward fo~tion of the 4-regioisomer. It can be presumed that both steric and electronic factors 1lC are involved. We find it difficult to accomodate our results with a two-step (i.e. diradical) view6 of these cycloadditions since this perception can not easily accommodate the changes in regiochemistry that we observe. We gratefully acknowledge the support obtained from the National Institutes of Health (GM 25303). References and Notes: 1. R. Huisgen, Angew. Chem. Int. Ed., Engl., 2, 565, 633 (1963).
ASJC Scopus subject areas
- Biochemistry
- Drug Discovery
- Organic Chemistry