Stereoselective synthesis of<i>cis</i>and<i>trans</i>four-membered cyclic nitrones
作者:Peter J. S. S. van Eijk、Cor Overkempe、Willem P. Trompenaars、David N. Reinhoudt、Lauri M. Manninen、Gerrit J. van Hummel、Sybolt Harkema
DOI:10.1002/recl.19881070202
日期:——
yield the trans four-membered cyclic nitrones 12–13 upon reaction with 6. Nitroalkene 4i reacts with 6c to give a 1:1 mixture of the cis and trans four-membered cyclic nitrones 9g and 13i. The trans stereochemistry of trans-N,N-diethyl-2, 3-dihydro-3-(2-methoxynaphthalenyl)-2-methyl-4-phenyl-2-azetecarboxamide 1-oxide (13k) was elucidated by means of X-ray analysis. Only from the reaction of 1-nitrocyclopentene
硝基烯烃3-5与乙撑胺(1-氨基乙炔)6反应生成四元环硝酮(2,3-二氢叠氮基1-氧化物)7-13。的硝基烯烃3和5C得到顺fourmembered环状硝酮7-11,而4和5B得到反式反应时fourmembered环状硝酮12-13与6。硝基烯烃4i与6c反应,生成1:1的顺式和反式四元环硝酮9g和13i混合物。这反式的立体化学反式- N,N-二乙基-2-,3-二氢-3-(2- methoxynaphthalenyl)-2-甲基-4-苯基-2- azetecarboxamide 1-氧化物(13K)通过X射线的装置阐明分析。仅从1-硝基环戊烯(5a)与最初形成的(4 + 2)环加合物6c的反应中,分离出了硝酸酯17。17的热环收缩产生3a,4、5、6-四氢-N,N-二甲基-3-苯基-3 H-环戊[c]异恶唑-3-羧酰胺(19),其结构由下式确定: X射线分析。该反式与顺式硝酮相比,四元环硝