A new synthetic approach to 5-dethia-4-methyl-5-oxacephems

Kałuża, Zbigniew; Kazimierski, Arkadiusz; Lewandowski, Krzysztof; Suwińska, Kinga; Szczęsna, Beata; Chmielewski, Marek

doi:10.1016/s0040-4020(03)00939-6

Cited by 20 publications

(4 citation statements)

References 24 publications

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“…Manipulation of protection of the hydroxyl groups on the 6-membered ring of 13 and Appel reaction of the resulting primary alcohol, afforded the iodide 14 24 . The diene 16 was made possible by the Barbier type addition of the allylchloride 15 25 with 14 , in the presence of zinc dust, providing the desired compound in good yield. Subsequently, ring-closing metathesis of 16 , using Grubbs 2 nd catalyst (10 mol%) under high dilution condition (0.01 M), afforded the cyclic compound 17 in excellent yield.…”

Section: Resultsmentioning

confidence: 99%

Antimalarial troponoids, puberulic acid and viticolins; divergent synthesis and structure-activity relationship studies

Sennari

Saito

Hirose

et al. 2017

Sci Rep

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Divergent synthesis of antimalarial troponoids, including naturally occurring compounds, some of which were identified and isolated by our group, has been achieved utilizing the total synthetic route of puberulic acid. Structure-activity relationships of natural products and simple troponoids inspired us to explore more detailed properties of this class of compounds. Access to new derivatives was facilitated through intermediate compounds generated during the total synthesis of puberulic acid by a stepwise oxidation-aromatization sequence to provide 7-hydroxytropolones and bromination for conversion of the carboxylic acid moiety. The first total synthesis of viticolin A, as well as the synthesis of different methyl-substituted derivatives, has also been achieved. In vitro antimalarial activity and cytotoxicity of novel derivatives were evaluated and fundamental information to facilitate the discovery of more promising antimalarials was obtained.

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Section: Resultsmentioning

confidence: 99%

Antimalarial troponoids, puberulic acid and viticolins; divergent synthesis and structure-activity relationship studies

Sennari

Saito

Hirose

et al. 2017

Sci Rep

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“…The lower result of the kinetic resolution of 22 in comparision with 9 is caused by the same reasons as suggested for 11 and 21. 11 Under the same conditions ee was found to be only 22% (Scheme 4).…”

Section: Scheme 2 Quinidine-catalyzed Nucleophilic Substitution Withmentioning

confidence: 92%

Quinidine catalyzed reaction between 4-formyloxy-azetidin-2-one and some thiophenols, thiols and alcohols

Chmielewski¹,

Kozioł²,

Altieri³

et al. 2011

Arkivoc

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Readily available 4-formyloxyazetidinone was enantioselectively transformed into 4-substituted azetidinones upon treatment with 0.1 equiv. of the cinchona alkaloid (quinidine) in toluene via intermolecular nucleophilic trapping of the N-acylimine intermediate by mercapto-, or hydroxymoieties of thiophenols, thiols, phenols and alcohols. Additionally, biological activity tests were performed on the newly synthesized β-lactams.

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“…5 The formation of the six-membered oxazine ring proceeded via an intramolecular ester condensation in 8. Very recently we have shown 6 that our new methodology, that utilizes the 4-vinyloxyazetidin-2-one (9) 7 as a starting synthon, opens an entry to a range of compounds possessing the 4-methyl-5-oxacepham skeleton, providing that the ethyl lactate is used as a chiral starting material (Scheme 1). The present paper describes the introduction of the alkoxycarbonyl function at C-2 of (4S,6R) 3-keto-4-methyl-5-oxacepham 10.…”

Section: Introductionmentioning

confidence: 99%