Syntheses with isoxazoles. II. Rearrangement of isoxazolo[2,3-a]pyridinium salts into 5,6-dihydro-4H-furo[3,2-b]pyridin-2-ones was written by Good, R. H.;Jones, Gurnos;Phipps, J. R.. And the article was included in Journal of the Chemical Society, Perkin Transactions 1 in 1972.Synthetic Route of C7H9NO3 This article mentions the following:
The 4,5,6,7-tetrahydro-4-oxoisoxazolo[2,3-a]pyridinium bromides (I, R = H, Me) on brief treatment with boiling Ac2O gave the 5,6-dihydro-4H-furo[3,2-b]pyridin-2-ones (II, R = H, Me, resp.); rearrangement via a ketene intermediate was suggested. The 5-bromo derivative of (I, R = H) in boiling Ac2O underwent cleavage of either the pyridine or the isoxazole ring. The mol. structure of II (R = H) was determined by x-ray crystallog. In the experiment, the researchers used many compounds, for example, Ethyl 4-methylisoxazole-3-carboxylate (cas: 38061-69-7Synthetic Route of C7H9NO3).
Ethyl 4-methylisoxazole-3-carboxylate (cas: 38061-69-7) belongs to isoxazole derivatives. Isoxazoles are aromatic heterocycles containing an N–O bond. Isoxazoles are commonly used as enaminoketone or β-diketone surrogate. Isoxazoles are potent isosteres of pyridine and have been found to inhibit voltage-gated sodium channels for pain control, for the construction of tetracycline antibiotic derivatives, and as a therapeutic agent for depression.Synthetic Route of C7H9NO3
Referemce:
Isoxazole – Wikipedia,
Isoxazole | C3H3NO – PubChem