The Structure and Physicochemical Properties of Isoxazole Derivatives

This decade has brought a number of investigations of the physicochemical properties of isoxazole derivatives and the elucidation of some details concerning their structure. The data obtained are in a good agreement with the conceptions as to the structure of isoxazole as reviewed by Barnes. We shall therefore be concerned only with recent work. 

The detailed study of dipole moments of isoxazole and its homo- 

The spectra of isoxazoles have recently been examined in detail. Pino et al. investigated the UV spectra of isoxazole and the methyl-isoxazoles. These spectra revealed characteristic shifts in the maxima depending on the number and position of methyl groups. Such regularities are characteristic only for aromatic systems. The shift is most marked for a C-4 methyl group, and is absent for a C-3 methyl group. 

Speroni, P. Pino, and L. Mori, Gazz. chim. ital. 82, 269 (1952). 

Speroni and L. Mori, Atti accad. nazl. Lincei, Rend. Classe sci. fis. mat. e nat. 12, 704 (1952). 

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