On the mechanism and stereochemistry of the formation of β-lactam derivatives of 2,4-disubstituted-2,3-dihydro-benzo[1,4]diazepines
作者:Hong-Zhong Wang、Xin Zhou、Jia-Xi Xu、Sheng Jin、Yue-Ming Li、AlbertS. C. Chan
DOI:10.1002/jhet.5570380503
日期:2001.9
ring boat conformation. The thus formed β-lactams should have four pairs of stereoisomers. However, only one pair of enantiomers (2S,2R,4R) and (2R,2aS,4S) was obtained. The mechanism and stereochemistry of the formation of these compounds were studied on the basis of nmr spectroscopy and further confirmed by X-ray diffraction.
2-氯-4-苯基2A-(4'-甲氧基苯基)-3,5- dihydroazatetracyclic [1,2 d ]苯并[1,4]二氮杂-1-酮(III一个)和2-氯-4-甲基2A-(4'-甲氧基苯基)-3,5- dihydroazatetracyclic [1,2 d ] -苯并[1,4]二氮杂-1-酮(III b)的合成。1-苯甲酰基-2-苯基-4-(4'-甲氧基苯基)[1,4]苯并二氮杂(II一)通过苯甲酰形成起始原料的2-苯基-4-(4'-甲氧基苯基) - [1,2 4]苯并二氮杂((I a)与七元环舟构象倒置。如此形成的β-内酰胺应具有四对立体异构体。但是,只有一对对映异构体(2 S,2 R,4得到R)和(2 R,2a S,4 S)。在NMR光谱学的基础上研究了这些化合物的形成机理和立体化学,并通过X射线衍射进一步证实。