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A Unified Route to theWelwitindolinone Alkaloids: Total Syntheses of ( − )- N -MethylwelwitindolinoneC Isothiocyanate, ( − )- N -MethylwelwitindolinoneC Isonitrile, and ( − )-3-Hydroxy- N -methylwelwitindolinoneC Isothiocyanate

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ABSTRACT

2a2b3a2a2b3a3a: As part of a comprehensive strategy to the welwitindolinonealkaloidspossessing a bicyclo[4.3.1]decane core, we report herein concise asymmetrictotal syntheses of (−)-N-methylwelwitindolinoneC isothiocyanate (), (−)-N-methylwelwitindolinoneC isonitrile (), and (−)-3-hydroxy-N-methylwelwitindolinone C isothiocyanate () from acommon tetracyclic intermediate. The crucial vinyl chloride moietywas installed through electrophilic chlorination of a hydrazone, butonly after adjustment of reactivity to circumvent a facile skeletalrearrangement. Selective desulfurization and oxidation of provided access to and , respectively.Notably, this work provides corrected 1H and 13C NMR spectral data for .

No MeSH data available.


Welwitindolinone alkaloids.
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fig1: Welwitindolinone alkaloids.

Mentions: In the continuing search foreffective new therapies to combat human disease, the field of medicinehas often benefited from the discovery of novel compounds isolatedfrom natural sources. As part of this pursuit, Moore and co-workersinvestigated a series of marine and terrestrial cyanobacteria andfound their lipophilic extracts to display an array of cytotoxic properties.1 This biological activity was traced to a newfamily of polycyclic oxindole-containing alkaloids—the welwitindolinones(e.g., 1–4, Figure 1). Nearly all members of this family possess a common bicyclo[4.3.1]decanering system set within a densely functionalized tetracyclic scaffold.Given their interesting biological activities and unique moleculararchitectures, the welwitindolinones have been the focus of numeroussynthesis groups for nearly 15 years.2,3 Early thisyear, we reported the first synthesis of a bridged bicyclic memberof the family, N-methylwelwitindolinone D isonitrile(4),4 and this was followedby the synthesis of dihydro-N-methylwelwitindolinoneB isothiocyanate.5 Most recently, Gargand co-workers completed a remarkable synthesis of (−)-N-methylwelwitindolinone C isothiocyanate (2a).6 As part of an ongoing program aimedat the development of a comprehensive approach toward this intriguingfamily of alkaloids, we now report the total syntheses of (−)-N-methylwelwitindolinone C isothiocyanate (2a), (−)-N-methylwelwitindolinone C isonitrile(2b), and (−)-3-hydroxy-N-methylwelwitindolinoneC isothiocyanate (3a).


A Unified Route to theWelwitindolinone Alkaloids: Total Syntheses of ( − )- N -MethylwelwitindolinoneC Isothiocyanate, ( − )- N -MethylwelwitindolinoneC Isonitrile, and ( − )-3-Hydroxy- N -methylwelwitindolinoneC Isothiocyanate
Welwitindolinone alkaloids.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3368435&req=5

fig1: Welwitindolinone alkaloids.
Mentions: In the continuing search foreffective new therapies to combat human disease, the field of medicinehas often benefited from the discovery of novel compounds isolatedfrom natural sources. As part of this pursuit, Moore and co-workersinvestigated a series of marine and terrestrial cyanobacteria andfound their lipophilic extracts to display an array of cytotoxic properties.1 This biological activity was traced to a newfamily of polycyclic oxindole-containing alkaloids—the welwitindolinones(e.g., 1–4, Figure 1). Nearly all members of this family possess a common bicyclo[4.3.1]decanering system set within a densely functionalized tetracyclic scaffold.Given their interesting biological activities and unique moleculararchitectures, the welwitindolinones have been the focus of numeroussynthesis groups for nearly 15 years.2,3 Early thisyear, we reported the first synthesis of a bridged bicyclic memberof the family, N-methylwelwitindolinone D isonitrile(4),4 and this was followedby the synthesis of dihydro-N-methylwelwitindolinoneB isothiocyanate.5 Most recently, Gargand co-workers completed a remarkable synthesis of (−)-N-methylwelwitindolinone C isothiocyanate (2a).6 As part of an ongoing program aimedat the development of a comprehensive approach toward this intriguingfamily of alkaloids, we now report the total syntheses of (−)-N-methylwelwitindolinone C isothiocyanate (2a), (−)-N-methylwelwitindolinone C isonitrile(2b), and (−)-3-hydroxy-N-methylwelwitindolinoneC isothiocyanate (3a).

View Article: PubMed Central - PubMed

ABSTRACT

2a2b3a2a2b3a3a: As part of a comprehensive strategy to the welwitindolinonealkaloidspossessing a bicyclo[4.3.1]decane core, we report herein concise asymmetrictotal syntheses of (−)-N-methylwelwitindolinoneC isothiocyanate (), (−)-N-methylwelwitindolinoneC isonitrile (), and (−)-3-hydroxy-N-methylwelwitindolinone C isothiocyanate () from acommon tetracyclic intermediate. The crucial vinyl chloride moietywas installed through electrophilic chlorination of a hydrazone, butonly after adjustment of reactivity to circumvent a facile skeletalrearrangement. Selective desulfurization and oxidation of provided access to and , respectively.Notably, this work provides corrected 1H and 13C NMR spectral data for .

No MeSH data available.