Cycloadditions of nitrile oxides to amidoximes. A general synthesis of 3,5-disubstituted 1,2,4-oxadiazole-4-oxides.
โ Scribed by Paolo Quadrelli; Anna Gamba Invernizzi; Mario Falzoni; Pierluigi Caramella
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- French
- Weight
- 578 KB
- Volume
- 53
- Category
- Article
- ISSN
- 0040-4020
No coin nor oath required. For personal study only.
๐ SIMILAR VOLUMES
We would like to report that aliphatic and aromatic nitrile oxides (I), as exemplified by pivalonitrile oxide and I-chlorobenzonitrile oxide respectively, react with methyl imidates (II) at room temperature (in absolute ether) to yield 1.2,4-oxadiazoles of the type III (See Table ).
The well established high synthetic utility of 2?-isoxazolines is due to their synthetic equivalency of a wide variety of important functionalized building blocks such as P-hydroxy ketones+ fi-amino alcohols, cr,punsaturated ketones, and related functionalities.' Nitrile oxide cyclctaddition offers
1,2,4-Oxadiazole-4-oxides undergo clean thermal cleavage in refluxing chlorobenzene or xylene to nitriles and nitrosocarbonyl intermediates, which are either trapped with suitable olefins to afford ene adducts or dimerize and rearrange to anhydrides.