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On the mechanism and stereochemistry of the formation of β‐lactam derivatives of 2,4‐disubstituted‐2,3‐dihydro‐benzo[1,4]diazepines
Author(s) -
Wang HongZhong,
Zhou Xin,
Xu JiaXi,
Jin Sheng,
Li YueMing,
Chan AlbertS. C.
Publication year - 2001
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570380503
Subject(s) - chemistry , stereochemistry , lactam , enantiomer , ring (chemistry) , nuclear magnetic resonance spectroscopy , benzodiazepine , organic chemistry , biochemistry , receptor
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.