Zur Kenntnis der Catechine und Catechingerbstoffe

Freudenberg, Karl; Weinges, Klaus

doi:10.1002/jlac.19545900207

Cited by 36 publications

(2 citation statements)

References 23 publications

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“…The failure of this polymer to give the vanillin reaction (Procter & Paessler, 1901) provides further evidence that polymerization involves the phloroglucinol residue of the monomer. The work of the Heidelberg School for 20 years has maintained (Freudenberg, 1956;Freudenberg & Maitland, 1934a, b;Freudenberg & Weinges, 1955) that phlobatannins from the barks of Acacia molli88ima, birch, chestnut (Ca8tanea sativa), eucalypts, mangrove, oak, spruce and willow and from the heartwood ofAcacia catechu and quebracho trees are catechins, polymerized po8t mortem by plant acids. Two mechanisms have been considered.…”

Section: Quercetinmentioning

confidence: 99%

Enzymic oxidation of catechin to a polymer structurally related to some phlobatannins

Hathway

Seakins

1957

Biochemical Journal

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Section: Quercetinmentioning

confidence: 99%

Enzymic oxidation of catechin to a polymer structurally related to some phlobatannins

Hathway

Seakins

1957

Biochemical Journal

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“…2‐Phenyl‐2 H ‐chromene (3d): The General Procedure with 1d (0.067 g, 0.51 mmol)/MeCN (0.5 mL)/PhMe (2.0 mL), 2a (0.668 g, 2.24 mmol)/MeCN (0.5 mL)/PhMe (2.0 mL) and CsF (0.467 g, 3.07 mmol) afforded 3d 27 (0.047 g, 45 %) as a clear oil {purified by flash chromatography [gradient eluents: petroleum ether/dichloromethane (20:1, v/v) containing triethylamine (3 ‰), then petroleum ether/ethyl acetate (80:1, v/v) containing triethylamine (3 ‰)]; R f = 0.71 [TLC eluent: petroleum ether/ethyl acetate (40:1, v/v)]}. 1 H NMR (400 MHz, [D 6 ]acetone): δ = 7.48–7.46 (m, 2 H), 7.39–7.30 (m, 3 H), 7.11 (td, J 1 = 7.6, J 2 = 1.2 Hz, 1 H), 7.07 (dd, J 1 = 7.4, J 2 = 1.4 Hz, 1 H), 6.86 (td, J 1 = 7.2, J 2 = 1.2 Hz, 1 H), 6.74 (d, J = 8.0 Hz, 1 H), 6.61 (d, J = 9.6 Hz, 1 H), 5.96–5.94 (m, 1 H), 5.92 (dd, J 1 = 9.6, J 2 = 3.6 Hz, 1 H) ppm.…”

Section: Methodsmentioning

confidence: 99%

A Facile Synthesis of 2H‐Chromenes and 9‐Functionalized Phenanthrenes through Reactions between α,β‐Unsaturated Compounds and Arynes

Zhang

Huang

2012

Eur J Org Chem

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Facile syntheses of 2H‐chromenes or 9‐functionalized phenanthrenes under mild conditions in moderate to good yields have been developed. They each involve annulations of arynes with α,β‐unsaturated compounds bearing different electron‐withdrawing groups (EWGs). Depending on the natures of the different EWGs, the reactions proceed by different pathways: enals react with arynes through a tandem [2+2] cycloaddition/thermal electrocyclic ring‐opening/6e‐electrocyclization sequence to afford 2H‐chromenes, whereas acyl‐/ethoxycarbonyl‐/cyano‐substituted styrenes undergo Diels–Alder reactions with arynes followed by aromatization to afford 9‐functionalized phenanthrenes. The scope, limitations, regioselectivities and mechanisms have been studied and are discussed in detail.

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Acylation and Alkylation

Roper¹,

Gehrer²,

Narbeshuber³

et al. 2000

Ullmann's Encyclopedia of Industrial Chemistry

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The article contains sections titled: 1. Introduction 1.1. Catalysts 1.1.1. Acidic Catalysts 1.1.2. Basic Catalysts 1.1.3. Organometallic Catalysts 1.2. Alkylating and Acylating Agents 1.3. Mechanism 1.3.1. Alkylation 1.3.2. Acylation 2. Alkylation and Acylation of Aromatic Compounds 2.1. Alkylation 2.1.1. Alkylation of Benzene 2.1.2. Cycloalkylation 2.1.3. Alkylation of Substituted Benzenes 2.1.4. Alkylation of Phenols 2.1.5. Alkylation of Aromatic Amines 2.1.6. Alkylation of Heteroaromatic Compounds and Related Substrates 2.1.7. Miscellaneous Alkylation Reactions 2.2. Acylation 2.2.1. Acylation of Benzene and Benzene Derivatives 2.2.2. Acylation of Polynuclear Aromatic Compounds 2.2.3. Acylation of Heteroaromatic Compounds 2.2.4. Acylation of Nonbenzenoid Aromatic Compounds 2.2.5. Miscellaneous Acylation Reactions 3. Acylation and Alkylation of Aliphatic Hydrocarbons 4. N ‐Alkylation and N ‐Acylation 4.1. N ‐Alkylation 4.1.1. N ‐Alkylation by Alcohols or Ethers 4.1.2. N ‐Alkylation by Alkyl Halides 4.1.3. N ‐Alkylation by Olefins 4.1.4. N ‐Alkylation by Carbonyl Compounds (Reductive Alkylation) 4.2. N ‐Acylation 5. O ‐Alkylation and O ‐Acylation 5.1. Synthesis of Esters 5.2. Synthesis of Anhydrides 5.3. Synthesis of Ethers 6. CH ‐Alkylation and CH ‐Acylation of Nonaromatic Compounds 7. Synthesis of Metal Alkyls

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Zur Kenntnis der Catechine und Catechingerbstoffe

Cited by 36 publications

References 23 publications

Enzymic oxidation of catechin to a polymer structurally related to some phlobatannins

Enzymic oxidation of catechin to a polymer structurally related to some phlobatannins

A Facile Synthesis of 2H‐Chromenes and 9‐Functionalized Phenanthrenes through Reactions between α,β‐Unsaturated Compounds and Arynes

Acylation and Alkylation

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