The [1,4]oxazino[4,3-a]azepine ring system: Construction from morpholinoallenes and a structural study
作者:Gerhard Maas、Berthold Manz、Theo Mayer、Udo Werz
DOI:10.1016/s0040-4020(98)01132-6
日期:1999.1
Morpholinoallenes 4 react with dimethyl and di(tert-butyl) acetylenedicarboxylate to form 4-alkylidene-3-morpholino-1-cyclobutenes 7 which undergo thermal rearrangement to [1,4]oxazino[4,3-a]azepine derivatives 8 and 9. The structures of 7a, 8aA, and 8c have been determined by single-crystal X-ray diffraction. A cis-fusion of the chair-like morpholine ring and the dihydroazepine ring is found in both
吗啉代烯丙基4与二甲基和二(叔丁基)乙炔基二羧酸酯反应形成4-亚烷基-3-吗啉代-1-环丁烯7,将其热重排为[1,4]恶嗪基[4,3- a ] a庚因衍生物8和9。7a,8aA和8c的结构已通过单晶X射线衍射确定。在8aA和8c中都发现了椅子样吗啉环和二氢氮杂ring环的顺式融合,但角氢原子在8aA中是赤道的,而在8c中是轴向的。NMR研究表明,固态的吗啉环的各个椅构象在溶液中也是有利的,但是温度可变的光谱表明发生了环反转。