Tucker, H. et al. published their research in Tetrahedron Letters in 1981 | CAS: 5765-44-6

5-Methylisoxazole (cas: 5765-44-6) belongs to isoxazole derivatives. Isoxazoles are aromatic heterocycles containing an N–O bond. Isoxazoles are commonly used as enaminoketone or β-diketone surrogate. The electrophilic cyclization of various 2-alkynone O-methyl oximes with a wide range of substrates such as ICl, I2, Br2, PhSeBr, etc. provides a variety of 3,4,5-trisubstituted isoxazoles in good to excellent yields.Application of 5765-44-6

The cyclodimerization of 3-methyl-2-butenenitrile was written by Tucker, H.;Golding, G.;Purvis, S. R.. And the article was included in Tetrahedron Letters in 1981.Application of 5765-44-6 This article mentions the following:

Treatment of RCMe:CHCN (R = Me, Et) with Li(NHCHMe2)2 between -78° and 0° (MeOCH2CH2OMe) gave the cyclic dimers I. The mechanism of this dimerization is discussed in terms of an allylic anion intermediate. On this basis, the product for the base-catalyzed dimerization of CH2:CMeCH2CN, previously reported to be II (Takabe, K.; et al., 1980) was reassigned as I. In the experiment, the researchers used many compounds, for example, 5-Methylisoxazole (cas: 5765-44-6Application of 5765-44-6).

5-Methylisoxazole (cas: 5765-44-6) belongs to isoxazole derivatives. Isoxazoles are aromatic heterocycles containing an N–O bond. Isoxazoles are commonly used as enaminoketone or β-diketone surrogate. The electrophilic cyclization of various 2-alkynone O-methyl oximes with a wide range of substrates such as ICl, I2, Br2, PhSeBr, etc. provides a variety of 3,4,5-trisubstituted isoxazoles in good to excellent yields.Application of 5765-44-6

Referemce:
Isoxazole – Wikipedia,
Isoxazole | C3H3NO – PubChem