Stereoselective synthesis of optically active bicyclic β-lactam carboxylic acids that target pilus biogenesis in pathogenic bacteriaElectronic supplementary information (ESI) available: 13C NMR spectra of 7(a–g), 10–14, 16(a and d) and 17(a–b). See http://www.rsc.org/suppdata/ob/b2/b210551a/
Stereoselective Synthesis of Optically Active β-Lactams, Potential Inhibitors of Pilus Assembly in Pathogenic Bacteria
作者:Hans Emtenäs、Gabe Soto、Scott J. Hultgren、Garland R. Marshall、Fredrik Almqvist
DOI:10.1021/ol0059899
日期:2000.7.1
[reaction: see text] Opticallyactive beta-lactams 3 are obtained in excellent yields (up to 93%) and with complete stereoselectivity from Meldrum's acid derivatives 1 and Delta(2)-thiazolines 2. A selective reduction to aldehydes 5 (R = Ar or CH(2)Ar) was then accomplished by using DIBAL-H. This rigid framework, with stereochemistry different than that of penicillin, is designed to be a suitable scaffold
Cycloaddition of Δ<sup>2</sup>-Thiazolines and Acyl Ketenes under Acidic Conditions Results in Bicyclic 1,3-Oxazinones and Not 6-Acylpenams as Earlier Reported
作者:Nils Pemberton、Hans Emtenäs、Dan Boström、Peter J. Domaille、William A. Greenberg、Michael D. Levin、Zuolin Zhu、Fredrik Almqvist
DOI:10.1021/ol047528j
日期:2005.3.1
Optically active Delta(2)-thiazolines 4 were previously reported to react with acyl Meldrum's acid derivatives 5 under acidic conditions (HCI (g) in benzene) to stereoselectively give 6-acylpenams 1. Recently we have discovered that the structure elucidation of these compounds was incorrect. Thus, we report new data showing that instead of acyl beta-lactams, the optically active isomers 3R,9R-1,3-oxazinones 3a-g are obtained stereoselectively in 38-93% yields.
NAGAO, YOSHIMITSU;KUMAGAI, TOSHIO;TAKAO, SACHIKO;ABE, TAKAO;OCHIAI, MASAH+, J. CHEM. SOC. JAP., CHEM. AND IND. CHEM.,(1987) N 7, 1447-1456
One-Pot Synthesis of 2,4-Disubstituted Thiazoline from β-Azido Disulfide and Carboxylic Acid
作者:Yi Liu、Jun Liu、Xiangbing Qi、Yuguo Du
DOI:10.1021/jo301030k
日期:2012.8.17
A concise and efficient one-pot four-step synthesis of 2,4-disubstituted thiazoline via a cascade disulfide bond cleavage/thiocarbonylation/Staudinger reduction/aza-Wittig reaction is established. Treatment of various carboxylicacids with β-azido disulfides under this one-pot procedure obtained the desired thiazolines in good to excellent isolated yields.
Stereoselective synthesis of optically active bicyclic β-lactam carboxylic acids that target pilus biogenesis in pathogenic bacteriaElectronic supplementary information (ESI) available: 13C NMR spectra of 7(a–g), 10–14, 16(a and d) and 17(a–b). See http://www.rsc.org/suppdata/ob/b2/b210551a/
作者:Hans Emtenäs、Marcus Carlsson、Jerome S. Pinkner、Scott J. Hultgren、Fredrik Almqvist
DOI:10.1039/b210551a
日期:2003.4.14
Optically active bicyclic β-lactams were synthesized, starting from 2-H-Î2-thiazolines and Meldrum's acid derivatives. Several methods to accomplish an ester hydrolysis without damaging the β-lactam framework were investigated. A rapid CsOH saponification of the β-lactam methyl esters was developed and protonation of the Cs-carboxylates by Amberlite (IR-120 H+) afforded a series of bicyclic β-lactam carboxylic acids. Moreover, a convenient method for the synthesis of 2-H-Î2-thiazolinecarboxylic acid methyl ester 2 was developed. Bicyclic β-lactam carboxylic acids 7aâg and aldehydes 4aâd were screened for their affinity to the bacterial periplasmic chaperone PapD using a surface plasmon resonance technique. β-Lactams substituted with large acyl substituents showed better binding to the chaperone than the native C-terminal peptide PapG 8, demonstrating that bicyclic β-lactams constitute a new class of potential bacterial chaperone inhibitors.