Вид документа : Статья из журнала Шифр издания : 54/S 78 Автор(ы) : Sosnovskikh V. Ya., Sizov A. Yu., Usachev B. I., Kodess M. I., Anufriev V. A. Заглавие : Spiro[4H-chromene-4,5-isoxazolines] and related compounds: Synthesis and reactivities [Electronic resource] Место публикации : Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 2006. - Vol. 55, № 3. - С. 535-542 Систем. требования: http://www.springerlink.com/content/m9312486x4764n84/fulltext.pdf Примечания : 27.10.2011 г. ББК : 54 Предметные рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Reactions of chromones with methyl ketoximes in the presence of lithium diisopropylamide follow the nucleophilic 1,2-addition mechanism to give spiro[4H-chromene-4,5?-isoxazolines] in good yields. The isoxazoline ring in spiro[4H-chromene-4,5?-isoxazolines] undergoes opening under the action of conc. H2SO4, yielding ?,?-unsaturated oximes. Their nitrosation and bromination lead to the corresponding spiroisoxazolines, while the Beckmann rearrangement, to ?,?-unsaturated amides. The latter are also formed directly from spiro[4H-chromene-4,5?-isoxazolines] under the action of PCl5. N-Substituted acetophenone hydrazones in the presence of lithium diisopropylamide react at the C(4) atom of 2-trifluoromethylchromone, while acetophenone anil under the same conditions, at the C(2) atom Держатели документа: Центральная научная библиотека УрО РАН Доп.точки доступа: Sosnovskikh, V. Ya.; Sizov, A. Yu.; Usachev, B. I.; Kodess, M. I.; Кодесс Михаил Исаакович; Anufriev, V. A.