Asymmetric Synthesis and Antimicrobial Activity of Some New Mono and Bicyclic β-Lactams

Molecules

A. A. Jarrahpour¹  M. Shekarriz¹ 

[1] ¹Chemistry Department, College of Sciences, Shiraz University, Shiraz 71454, Iran ²Institute of Standards and Industrial Research of Iran, Shiraz 71447, Iran

关键词: D-Phenylalanine;    asymmetric induction;    chiral Schiff base;    DBU;    antimicrobial;   

DOI  :  10.3390/91100939

来源: mdpi

【 摘 要 】

Reaction of the amino acid D-phenylalanine ethyl ester (4) with cinnamaldehyde gave chiral Schiff base 5, which underwent an asymmetric Staudinger [2+2] cycloaddition reaction with phthalimidoacetyl chloride to give the monocyclic β-lactam 6 as a single stereoisomer. Ozonolysis of 6 followed by reduction with lithium aluminum tri(tert-butoxy) hydride afforded the hydroxymethyl β-lactam 8. Treatment of 8 with methansulfonyl chloride gave the mesylated monocyclic β-lactam 9, which was converted to the bicyclic β-lactam 10 upon treatment with 1,8-diazabicyclo[5,4.0] undec- 7-ene (DBU). Deprotection of the phthalimido group in β-lactams 6 and 10 by methylhydrazine and subsequent acylation of the free amino β-lactams with different acyl chlorides in the presence of pyridine afforded mono and bicyclic β-lactams 14a-d and 15a-d respectively. The compounds prepared were tested against Escherichia coli, Staphilococcus citrus, Klebsiella pneumanie and Bacillus subtillis. Some of these compounds showed potential antimicrobial activities.

【 授权许可】

CC BY   
This is an open access article distributed under the Creative Commons Attribution License (CC BY) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.