Вид документа : Статья из журнала Шифр издания : 54/N 89 Автор(ы) : Sosnovskikh V. Ya., Usachev B. I., Sizov A. Yu., Kodess M. I. Заглавие : Novel chemical modifications at the 4-position of chromones. Synthesis and reactivity of 4H-chromene-4-spiro-5-isoxazolines and related compounds Место публикации : Tetrahedron Letters. - 2004. - Vol. 45, № 39. - С. 7351-7354: ил. Примечания : Библиогр.: с. 7353-7354 (22 ref.) ББК : 54 Предметные рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Reactions of chromones with dilithiooximes proceed via nucleophilic 1,2-addition to give, on acidification, 4H-chromene-4-spiro-5-isoxazoline derivatives in high yields. On treatment with concentrated H2SO4 the isoxazoline ring of this novel spiroannulated heterocyclic system opens to give alfa,beta-unsaturated oximes, which undergo nitrosation, bromination, and the Beckmann rearrangement to the corresponding spiroisoxazolines and alfa,beta-unsaturated amides, respectively. The latter can be obtained directly by the Beckmann rearrangement of 4H-chromene-4-spiro-5`-isoxazolines Держатели документа: Центральная научная библиотека УрО РАН Доп.точки доступа: Sosnovskikh, V. Ya.; Usachev, B. I.; Sizov, A. Yu.; Kodess, M. I.; Кодесс Михаил Исаакович