Synthesis of Novel 6-.ALPHA. and 6-.BETA.-Alkylcarbonylmethyl Substituted Penems.

Pentassuglia, Giorgio; Tarzia, Giorgio; Andreotti, Daniele; Bismara, C.; Carlesso, R.; Donati, Daniele; Gaviraghi, G.; Perboni, Alcide; Pezzoli, A.; Rossi, Tiziana; Tamburini, B.; Ursini, A.

doi:10.7164/antibiotics.48.399

Cited by 5 publications

(2 citation statements)

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“…The exclusive preference for the formation of the cis- lactam is caused by steric hindrance exerted by the β - aryl substituent. Our observation is in agreement with results of hydrogenation of structurally similar α-alkylidene-β-lactams reported previously. , An attempt to employ other hydrogenation methods, such as the Stryker’s reagent, resulted in the formation of a rather complex reaction mixture out of which only a small amount (∼30%) of the cis- products was isolated. In order to convert the cis -lactam 4 to the desired trans -lactam, epimerization by using 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) in DMSO was applied.…”

Section: Resultssupporting

confidence: 92%

Stereoselective Synthesis of Ezetimibe via Cross-Metathesis of Homoallylalcohols and α-Methylidene-β-Lactams

et al. 2016

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Ru-catalyzed cross-metathesis (CM) reaction between β-arylated α-methylidene-β-lactams and terminal olefins was developed. The CM reaction is effectively catalyzed with Hoveyda-Grubbs second-generation catalyst affording corresponding α-alkylidene-β-aryl-β-lactams in good isolated yields (41-83%) with exclusive Z-selectivity. The developed protocol was successfully applied for stereoselective preparation of Ezetimibe, the commercial cholesterol absorption inhibitor.

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Section: Resultssupporting

confidence: 92%

Stereoselective Synthesis of Ezetimibe via Cross-Metathesis of Homoallylalcohols and α-Methylidene-β-Lactams

et al. 2016

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“…In the published syntheses, enantiomerically pure 4-acetoxy 12, (29)(30)(31)(32)(33)(34)(35)(36)(37) was employed in the addition reaction even though stereochemistry of the carbon atom at the position four is lost in the course of the reaction. The addition is thought to take place at the sp2 hybridized carbon atom of the iminium ion.…”

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The Synthesis of a Series of Fluorinated Tribactams

Gyenes

Kornilov

Welch

1999

ACS Symposium Series

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A fluorinated building block was converted in a concise series of steps to a new series of fluorinated tribactams. During the course of the synthesis an interesting stereoselective addition, presumably influenced by the presence of fluorine was discovered. The products were carefully characterized by 2D NMR spectroscopic methods.The search for novel antimicrobial agents containing the β-lactam motif has produced a plethora of novel chemical entities many of which are presently marketed as antibiotic agents. The report of the discovery of thienamycin opened a new frontier in β-lactam research. Since then, other advances in the chemistry and biology of the carbapenems have followed. Recently, scientists at Glaxo Wellcome have discovered the "trinem" family(l-5) of synthetic β-lactams (See below). Functionalization at the C-4 position of a cyclohexane ring fused to the carbapenem nucleus has been very effective at modifying the activity of the trinems. The main structural features of these tricyclic β-lactam derivatives (also known as tribactams) are the presence of a reactive β-lactam ring (A) with hydroxyethyl substituent, an unsaturated five-membered ring (B), and a six-membered carbocyclic ring (C).

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ChemInform Abstract: Synthesis of Novel 6‐α and 6‐β‐Alkylcarbonylmethyl Substituted Penems.

Pentassuglia¹,

Tarzia²,

Andreotti³

et al. 1995

ChemInform

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Synthesis of Novel 6-α and 6-β-Alkylcarbonylmethyl Substituted Penems.-The antibacterial activity of novel title compounds (IV), (VII) is studied. 6-β-Alkylcarbonylmethyl penems are more active than the corresponding 6-α-analogues. Good activity is only achieved against Grampositive bacteria. -(PENTASSUGLIA, G.; TARZIA, G.; ANDREOTTI, D.; BISMARA, C.; CARLESSO, R.; DONATI, D.; GAVIRAGHI, G.; PERBONI, A.; PEZZOLI, A.; ROSSI, T.; TAMBURINI, B.; URSINI, A.; J.

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Synthesis of Novel 6-.ALPHA. and 6-.BETA.-Alkylcarbonylmethyl Substituted Penems.

Cited by 5 publications

References 0 publications

Stereoselective Synthesis of Ezetimibe via Cross-Metathesis of Homoallylalcohols and α-Methylidene-β-Lactams

Stereoselective Synthesis of Ezetimibe via Cross-Metathesis of Homoallylalcohols and α-Methylidene-β-Lactams

The Synthesis of a Series of Fluorinated Tribactams

ChemInform Abstract: Synthesis of Novel 6‐α and 6‐β‐Alkylcarbonylmethyl Substituted Penems.

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