β-Lactams: retrospect and prospect

Mukerjee, A. K.; Singh, Anamika

doi:10.1016/0040-4020(78)80209-9

Cited by 146 publications

(25 citation statements)

References 245 publications

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“…A solution of phthalimidoacetyl chloride was slowly added at -10 o C to a solution of chiral Schiff base 5 and triethylamine in dry methylene chloride. This method of addition produced the cis β-lactam 6 as a single stereoisomer in 80% yield [13][14][15][16]. The expected cisconfiguration of 6 was confirmed by 1 H-NMR, which showed a characteristic coupling constant of about 5 Hz for the β-lactam protons [17][18].…”

Section: Resultsmentioning

confidence: 85%

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

Jarrahpour

Shekarriz

Taslimi³

2004

Molecules

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Abstract: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.

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Section: Resultsmentioning

confidence: 85%

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

Jarrahpour

Shekarriz

Taslimi³

2004

Molecules

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“…Acetoxy, Methylthio und Halogen in Position 4 sind, in Abhängigkeit vom Substitutionsmuster des 2-Azetidinonringes, als gute Abgangsgruppen bekannt [2]. Der Einsatz des Acetoxyrestes als Fluchtgruppe ist begrenzt.…”

Section: Ergebnisse Und Diskussionunclassified

“…1-Substituierte dagegen benötigen Mineralsäure-bzw. Lewissäure-Katalyse [2], welche in vielen Fällen zu Ringöffnungen führt. Die Methylthiogruppe ist in mehrfacher Hinsicht verwendbar.…”

Section: Ergebnisse Und Diskussionunclassified

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Synthesis of 3,4-Benzo-1-oxacephem / Synthesis of 3,4-Benzo-1-oxacephem

Ongania

1985

Zeitschrift Für Naturforschung B

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The thioformimidate 4, which may be obtained by S-methylation of 5 reacts with chloroacetyl chloride/triethylamine to yield the trans-2-azetidinone 7. 7 is dehalogenated to 8. Removal of the protective group leads to 9, which undergoes ring closure by the action with mercuric chloride/ mercuric oxide. Chlorolysis of 8 and the subsequent reaction with hydrofluoric acid/acetonitrile yields 12. The treatment of 12 with silver tetrafluoroborate/silver oxide gives also the title compound 10

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“…Accordingly, the researches on synthesis, 1 biological activity, [2][3][4][5] and applications of β-lactams in organic synthesis, 6-13, have been reviewed from time to time. 1, [14][15][16][17][18][19] This article aims to update the reports on synthesis of monocyclic β-lactams during last five years. …”

Section: Introductionmentioning

confidence: 99%

Advances in synthesis of monocyclic beta-lactams

Singh¹,

Sudheesh²

2014

Arkivoc

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Recent years have witnessed significant advancement in cycloaddition and cyclization strategies for the synthesis of monocyclic β-lactams. Cycloadditions include the Staudinger's keteneimine cycloaddtions and related reaction. Cyclization reactions are reported to furnish β-lactams through N 1 -C 2 , N 1 -C 4 and C 3 -C 4 bond formations employing substrates like β-amino esters, β-amino alcohols, β-hydroxamate esters, and α-amino diazocarbonyls, etc. Some other strategies are silyl carbonylation reactions, ring-enlargement of aziridines, cleavage of one ring of a bicyclic β-lactam, and functional group transformations on the β-lactam rings. Recently, some multi-component reactions have also been designed. This article reviews the advances made in synthetic approaches to monocyclic β-lactams during last five years.

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β-Lactams: retrospect and prospect

Cited by 146 publications

References 245 publications

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

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

Synthesis of 3,4-Benzo-1-oxacephem / Synthesis of 3,4-Benzo-1-oxacephem

Advances in synthesis of monocyclic beta-lactams

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