A new amine catalyzed synthesis of 2-substituted 2,3-dihydro-4H-1,3-benzoxazin-4-ones
作者:Ronald B. Gammill
DOI:10.1021/jo00329a041
日期:1981.7
GAMMILL, R. B., J. ORG. CHEM., 1981, 46, N 16, 3340-3342
作者:GAMMILL, R. B.
DOI:——
日期:——
A facile approach for the synthesis of novel xanthene derivatives with Vilsmeier–Haack reagent
作者:Oleg K. Farat、Ivan V. Ananyev、Svetlana A. Varenichenko、Ekaterina V. Zaliznaya、Victor I. Markov
DOI:10.1007/s10593-019-02416-6
日期:2019.1
A series of new derivatives of formylxanthenes have been synthesized via the reaction of substituted 1,3-benzoxazines with Vilsmeier–Haack reagent. It has been shown that 1,3-benzoxazines unsubstituted in the aromatic part and 6-bromo-1,3-benzoxazines are rearranged into xanthene derivatives under heating at 80°C for 1.5 h. Substitution at the C-8 position of 1,3-benzoxazines, especially with electronegative
The dihydrobenzoxazone 9e, which is easily prepared from salicylamide 11 and cyclohexanone, serves as an efficient auxiliary in the synthesis of the 1-beta-methylcarbapenem key intermediate 10. The stereocontrolled Reformatsky-type reactions of the acetoxyazetidinone 2 with the carboximides 6 gave the intermediates 7 with high diastereoselectivities in high chemical yields. The auxiliary 9e also acts