Synthesis of sophorol, violanone, lonchocarpan, claussequinone, philenopteran, leiocalycin, and some other natural isoflavonoids by the oxidative rearrangement of chalcones with thallium(III) nitrate

Lorànd Farkas, Àgnes Gottsegen, Mihàly Nógrádi, Sàndor Antus

Research output: Article

114 Citations (Scopus)

Abstract

Isoflavones are conveniently prepared by the oxidative rearrangement of 2′-hydroxy- or 2′-acetoxy-chalcones with thallium(III) nitrate in methanol into 1-(2-hydroxyphenyl)-3,3-dimethoxy-2-phenylpropan-1-ones [e.g. (46)] followed by cyclisation, and the following natural isoflavonoids were synthesised in this way: the isoflavanones sophorol (49) and violanone (68), the isoflavans vestitol (57), duartin (58), mucronulatol (59), laxifloran (60), and lonchocarpan (61), the isoflavan quinones mucroquinone (66) and claussequinone (67), the pterocarpans philenopteran (69), leiocalycin (54), and 2-hydroxy-3-methoxy-8,9-methylenedioxy-6a,11a-dihydropterocarpan (56). Acid catalysed cyclisation of 1-(2-hydroxy-4-methoxyphenyl)-2-(2-hydroxy-4,5-methylenedioxyphenyl)-3,3- dimethoxypropan-1-one (48) gave no isoflavone but the two tetracyclic compounds, (53) (a derivative of 2-methoxypterocarp-6-ene) and (52) (a benzofuro[2,3-b][1]benzopyran). Claussequinone (67) was rapidly formed by autoxidation of its hydroquinone precursor (64), suggesting that oxidation may also have occurred during the isolation of the metabolite.

Original languageEnglish
Pages (from-to)305-312
Number of pages8
JournalJournal of the Chemical Society, Perkin Transactions 1
Publication statusPublished - 1974

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Chalcones
Isoflavones
Thallium
Cyclization
Nitrates
Pterocarpans
Benzopyrans
Quinones
Metabolites
Methanol
Derivatives
Oxidation
Acids
claussequinone
sophorol
duartin
vestitol
isoflavanone
hydroquinone
mucronulatol

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

@article{400bd29c495446d0921d8879fddc2a53,
title = "Synthesis of sophorol, violanone, lonchocarpan, claussequinone, philenopteran, leiocalycin, and some other natural isoflavonoids by the oxidative rearrangement of chalcones with thallium(III) nitrate",
abstract = "Isoflavones are conveniently prepared by the oxidative rearrangement of 2′-hydroxy- or 2′-acetoxy-chalcones with thallium(III) nitrate in methanol into 1-(2-hydroxyphenyl)-3,3-dimethoxy-2-phenylpropan-1-ones [e.g. (46)] followed by cyclisation, and the following natural isoflavonoids were synthesised in this way: the isoflavanones sophorol (49) and violanone (68), the isoflavans vestitol (57), duartin (58), mucronulatol (59), laxifloran (60), and lonchocarpan (61), the isoflavan quinones mucroquinone (66) and claussequinone (67), the pterocarpans philenopteran (69), leiocalycin (54), and 2-hydroxy-3-methoxy-8,9-methylenedioxy-6a,11a-dihydropterocarpan (56). Acid catalysed cyclisation of 1-(2-hydroxy-4-methoxyphenyl)-2-(2-hydroxy-4,5-methylenedioxyphenyl)-3,3- dimethoxypropan-1-one (48) gave no isoflavone but the two tetracyclic compounds, (53) (a derivative of 2-methoxypterocarp-6-ene) and (52) (a benzofuro[2,3-b][1]benzopyran). Claussequinone (67) was rapidly formed by autoxidation of its hydroquinone precursor (64), suggesting that oxidation may also have occurred during the isolation of the metabolite.",
author = "Lor{\`a}nd Farkas and {\`A}gnes Gottsegen and Mih{\`a}ly N{\'o}gr{\'a}di and S{\`a}ndor Antus",
year = "1974",
language = "English",
pages = "305--312",
journal = "Journal of the Chemical Society, Perkin Transactions 1",
issn = "1472-7781",
publisher = "Chemical Society",

}

TY - JOUR

T1 - Synthesis of sophorol, violanone, lonchocarpan, claussequinone, philenopteran, leiocalycin, and some other natural isoflavonoids by the oxidative rearrangement of chalcones with thallium(III) nitrate

AU - Farkas, Lorànd

AU - Gottsegen, Àgnes

AU - Nógrádi, Mihàly

AU - Antus, Sàndor

PY - 1974

Y1 - 1974

N2 - Isoflavones are conveniently prepared by the oxidative rearrangement of 2′-hydroxy- or 2′-acetoxy-chalcones with thallium(III) nitrate in methanol into 1-(2-hydroxyphenyl)-3,3-dimethoxy-2-phenylpropan-1-ones [e.g. (46)] followed by cyclisation, and the following natural isoflavonoids were synthesised in this way: the isoflavanones sophorol (49) and violanone (68), the isoflavans vestitol (57), duartin (58), mucronulatol (59), laxifloran (60), and lonchocarpan (61), the isoflavan quinones mucroquinone (66) and claussequinone (67), the pterocarpans philenopteran (69), leiocalycin (54), and 2-hydroxy-3-methoxy-8,9-methylenedioxy-6a,11a-dihydropterocarpan (56). Acid catalysed cyclisation of 1-(2-hydroxy-4-methoxyphenyl)-2-(2-hydroxy-4,5-methylenedioxyphenyl)-3,3- dimethoxypropan-1-one (48) gave no isoflavone but the two tetracyclic compounds, (53) (a derivative of 2-methoxypterocarp-6-ene) and (52) (a benzofuro[2,3-b][1]benzopyran). Claussequinone (67) was rapidly formed by autoxidation of its hydroquinone precursor (64), suggesting that oxidation may also have occurred during the isolation of the metabolite.

AB - Isoflavones are conveniently prepared by the oxidative rearrangement of 2′-hydroxy- or 2′-acetoxy-chalcones with thallium(III) nitrate in methanol into 1-(2-hydroxyphenyl)-3,3-dimethoxy-2-phenylpropan-1-ones [e.g. (46)] followed by cyclisation, and the following natural isoflavonoids were synthesised in this way: the isoflavanones sophorol (49) and violanone (68), the isoflavans vestitol (57), duartin (58), mucronulatol (59), laxifloran (60), and lonchocarpan (61), the isoflavan quinones mucroquinone (66) and claussequinone (67), the pterocarpans philenopteran (69), leiocalycin (54), and 2-hydroxy-3-methoxy-8,9-methylenedioxy-6a,11a-dihydropterocarpan (56). Acid catalysed cyclisation of 1-(2-hydroxy-4-methoxyphenyl)-2-(2-hydroxy-4,5-methylenedioxyphenyl)-3,3- dimethoxypropan-1-one (48) gave no isoflavone but the two tetracyclic compounds, (53) (a derivative of 2-methoxypterocarp-6-ene) and (52) (a benzofuro[2,3-b][1]benzopyran). Claussequinone (67) was rapidly formed by autoxidation of its hydroquinone precursor (64), suggesting that oxidation may also have occurred during the isolation of the metabolite.

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JO - Journal of the Chemical Society, Perkin Transactions 1

JF - Journal of the Chemical Society, Perkin Transactions 1

SN - 1472-7781

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