On the mechanism and stereochemistry of the formation of β-lactam derivatives of 2,4-disubstituted-2,3-dihydro-benzo[1,4]diazepines

✍ Scribed by Hong-Zhong Wang; Xin Zhou; Jia-Xi Xu; Sheng Jin; Yue-Ming Li; AlbertS. C. Chan

• Publisher: Journal of Heterocyclic Chemistry
• Year: 2001
• Tongue: English
• Weight: 92 KB
• Volume: 38
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570380503

✦ Synopsis

Abstract

2‐Chloro‐4‐phenyl‐2a‐(4′‐methoxyphenyl)‐3,5‐dihydroazatetracyclic [1,2‐d]benzo [ 1,4]diazepin‐1 ‐one (III~a~) and 2‐chloro‐4‐methyl‐2a‐(4′‐methoxyphenyl)‐3,5‐dihydroazatetracyclic[1,2‐d]‐benzo[1,4]diazepin‐1‐one (III~b~) were synthesized. 1‐Benzoyl‐2‐phenyl‐4‐(4′‐methoxyphenyl)[1,4]‐benzodiazepine (II~a~) was formed through benzoylation of starting material 2‐phenyl‐4‐(4′‐methoxyphenyl)‐[1,4]benzodiazepine (I~a~) with the inversion of seven‐member ring boat conformation. The thus formed β‐lactams should have four pairs of stereoisomers. However, only one pair of enantiomers (2__S__,2__R__,4__R__) and (2__R__,2a__S__,4__S__) 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.