The Synthesis of 5-Hydroxy-3-methylnaphtho[2,3-c]furan-4,9-dione and 5,8-Dihydroxy-1-methylnaphtho[2,3-c]furan-4,9-dione

Matthew Piggott, Dieter Wege

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15 Citations (Scopus)

Abstract

5-Hydroxy-3-methylnaphtho[2,3-c] furan-4,9-dione (1), a metabolite isolated from Aloe ferox and Bulbine capitata, has been synthesized by a sequence involving an annulation reaction between the anion of 4-methoxy-3-oxo-1,3-dihydroisobenzofuran-1-carbonitrile (8) and (E)-pent-3-en-2-one, followed by subsequent construction of the furan ring through allylic bromination, hydrolysis, and dehydration as the key steps. The formation of several unusual products observed in annulation reactions between (8) and O-protected derivatives of (E)-5-hydroxypent-3-en-2-one (9) can be rationalized by invoking the intermediacy of a reactive o-quinone methide. 5,8-Dihydroxy-1-methylnaphtho[2,3-c] furan-4,9-dione (2), another naturally occurring naphtho[2,3-c] furan-4,9-dione, has been prepared by a Friedel-Crafts acylation of 1,4-dimethoxybenzene with 2-methylfuran-3,4-dicarbonyl dichloride. Arguments are presented that 5,8-dihydroxynaphtho[2,3-c] furan-4,9-dione is a better structural representation than the alternative 4,9-dihydroxynaphtho[2,3-c] furan-5,8-dione tautomer in such systems, as the latter would contain a reactive isobenzofuran moiety.
Original languageEnglish
Pages (from-to)691-702
JournalAustralian Journal of Chemistry
Volume56
Issue number7
DOIs
Publication statusPublished - 2003

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Acylation
Metabolites
Dehydration
Anions
furan
Hydrolysis
Derivatives
1,4-dimethoxybenzene
2-methylfuran
quinone methide

Cite this

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title = "The Synthesis of 5-Hydroxy-3-methylnaphtho[2,3-c]furan-4,9-dione and 5,8-Dihydroxy-1-methylnaphtho[2,3-c]furan-4,9-dione",
abstract = "5-Hydroxy-3-methylnaphtho[2,3-c] furan-4,9-dione (1), a metabolite isolated from Aloe ferox and Bulbine capitata, has been synthesized by a sequence involving an annulation reaction between the anion of 4-methoxy-3-oxo-1,3-dihydroisobenzofuran-1-carbonitrile (8) and (E)-pent-3-en-2-one, followed by subsequent construction of the furan ring through allylic bromination, hydrolysis, and dehydration as the key steps. The formation of several unusual products observed in annulation reactions between (8) and O-protected derivatives of (E)-5-hydroxypent-3-en-2-one (9) can be rationalized by invoking the intermediacy of a reactive o-quinone methide. 5,8-Dihydroxy-1-methylnaphtho[2,3-c] furan-4,9-dione (2), another naturally occurring naphtho[2,3-c] furan-4,9-dione, has been prepared by a Friedel-Crafts acylation of 1,4-dimethoxybenzene with 2-methylfuran-3,4-dicarbonyl dichloride. Arguments are presented that 5,8-dihydroxynaphtho[2,3-c] furan-4,9-dione is a better structural representation than the alternative 4,9-dihydroxynaphtho[2,3-c] furan-5,8-dione tautomer in such systems, as the latter would contain a reactive isobenzofuran moiety.",
author = "Matthew Piggott and Dieter Wege",
year = "2003",
doi = "10.1071/CH02253",
language = "English",
volume = "56",
pages = "691--702",
journal = "Australian Journal of Chemistry:an international journal for chemical science",
issn = "0004-9425",
publisher = "CSIRO Publishing",
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T1 - The Synthesis of 5-Hydroxy-3-methylnaphtho[2,3-c]furan-4,9-dione and 5,8-Dihydroxy-1-methylnaphtho[2,3-c]furan-4,9-dione

AU - Piggott, Matthew

AU - Wege, Dieter

PY - 2003

Y1 - 2003

N2 - 5-Hydroxy-3-methylnaphtho[2,3-c] furan-4,9-dione (1), a metabolite isolated from Aloe ferox and Bulbine capitata, has been synthesized by a sequence involving an annulation reaction between the anion of 4-methoxy-3-oxo-1,3-dihydroisobenzofuran-1-carbonitrile (8) and (E)-pent-3-en-2-one, followed by subsequent construction of the furan ring through allylic bromination, hydrolysis, and dehydration as the key steps. The formation of several unusual products observed in annulation reactions between (8) and O-protected derivatives of (E)-5-hydroxypent-3-en-2-one (9) can be rationalized by invoking the intermediacy of a reactive o-quinone methide. 5,8-Dihydroxy-1-methylnaphtho[2,3-c] furan-4,9-dione (2), another naturally occurring naphtho[2,3-c] furan-4,9-dione, has been prepared by a Friedel-Crafts acylation of 1,4-dimethoxybenzene with 2-methylfuran-3,4-dicarbonyl dichloride. Arguments are presented that 5,8-dihydroxynaphtho[2,3-c] furan-4,9-dione is a better structural representation than the alternative 4,9-dihydroxynaphtho[2,3-c] furan-5,8-dione tautomer in such systems, as the latter would contain a reactive isobenzofuran moiety.

AB - 5-Hydroxy-3-methylnaphtho[2,3-c] furan-4,9-dione (1), a metabolite isolated from Aloe ferox and Bulbine capitata, has been synthesized by a sequence involving an annulation reaction between the anion of 4-methoxy-3-oxo-1,3-dihydroisobenzofuran-1-carbonitrile (8) and (E)-pent-3-en-2-one, followed by subsequent construction of the furan ring through allylic bromination, hydrolysis, and dehydration as the key steps. The formation of several unusual products observed in annulation reactions between (8) and O-protected derivatives of (E)-5-hydroxypent-3-en-2-one (9) can be rationalized by invoking the intermediacy of a reactive o-quinone methide. 5,8-Dihydroxy-1-methylnaphtho[2,3-c] furan-4,9-dione (2), another naturally occurring naphtho[2,3-c] furan-4,9-dione, has been prepared by a Friedel-Crafts acylation of 1,4-dimethoxybenzene with 2-methylfuran-3,4-dicarbonyl dichloride. Arguments are presented that 5,8-dihydroxynaphtho[2,3-c] furan-4,9-dione is a better structural representation than the alternative 4,9-dihydroxynaphtho[2,3-c] furan-5,8-dione tautomer in such systems, as the latter would contain a reactive isobenzofuran moiety.

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DO - 10.1071/CH02253

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SP - 691

EP - 702

JO - Australian Journal of Chemistry:an international journal for chemical science

JF - Australian Journal of Chemistry:an international journal for chemical science

SN - 0004-9425

IS - 7

ER -