a mixture of meso and dl diol 7 to be easily transformed into the corresponding bicyclooctane 2a and 3a with formaldehyde and acetonitrile as solvent. In water, however, the reaction selectively produces imidazolidine 4a. Based on NMR analysis, the major diastereomers were assigned as syn derivatives. X-ray crystal structure of 4a shows a planar configuration for imidazolidine ring, in line with two
2-
氨基吡啶与
乙二醛的缩合对内消旋和dl二醇7的混合物具有高选择性,从而易于以
甲醛和
乙腈为溶剂转化为相应的双
环辛烷2a和3a。然而,在
水中,该反应选择性地产生
咪唑烷4a。基于NMR分析,主要的非对映异构体被指定为顺式衍
生物。4a的X射线晶体结构显示了
咪唑烷环的平面构型,与两个端基异构作用一致,第一个为强相互作用,第二为弱相互作用。
吡啶基氮和羟基氢之间的氢键网络形成了十二个原子,形成椅子状构型。