Anthraquinone dye intermediates as precursors of aklavinone-type anthracyclinones

Cava, Michael P.; AHMED, Z.; Benfaremo, Nicholas; Murphy, Raymond A.; O'Malley, Gerard J.

doi:10.1016/s0040-4020(01)91538-8

Cited by 24 publications

(9 citation statements)

References 20 publications

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“…The first approach is outlined in Scheme . The known iodide 3 , prepared simply in two steps from chrysazin ( 2 ), , was subjected to a Heck reaction with methyl acrylate, under standard conditions, initially providing a mixture of the expected coupling product 4 and the corresponding phenol 5 resulting from deacetylation. Deprotection of the phenol was actually desired, and was forced to completion by the addition of water to the reaction mixture once the Heck coupling was complete, affording 5 exclusively, in excellent yield.…”

Section: Resultsmentioning

confidence: 99%

“…The concentrations of solutions of n - and sec -BuLi were determined by titration with N -benzylbenzamide . 1-Hydroxy-8-acetoxy-9,10-athraquinone was prepared from chrysazin ( 2 ) by a known method and N , N -Diisopropyl-2-methoxybenzamide ( 9b ) were prepared by known methods from o -anisic acid.…”

Section: Methodsmentioning

confidence: 99%

“…Iodic acid (4.38 g, 24.9 mmol) was added to a stirred mixture of 1-hydroxy-8-acetoxy-9,10-anthraquinone (7.06 g, 25.0 mmol) in water (60 mL) and dioxane (190 mL). Iodine (3.17 g, 12.5 mmol) was added, and the resulting mixture was heated at reflux for 18 h before being cooled to room temperature.…”

Section: Methodsmentioning

confidence: 99%

“…91 1-Hydroxy-8acetoxy-9,10-athraquinone was prepared from chrysazin (2) by a known method. 18 N,N-Diethyl-2-methoxybenzamide 92 and N,N-Diisopropyl-2-methoxybenzamide (9b) 93 were prepared by known methods from o-anisic acid. Dimethyl 3-hydroxy-6-methyl phthalate 94 was prepared according to a known method.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

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What Is the Structure of the Antitubercular Natural Product Eucapsitrione?

et al. 2017

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1,5,7-Trihydroxy-6H-indeno[1,2-b]anthracene-6,11,13-trione (1), proposed to be the antitubercular natural product eucapsitrione, has been synthesized in 43% overall yield and six steps, including a key Suzuki-Miyaura biaryl coupling and a directed remote metalation (DReM)-initiated cyclization. The physical and spectroscopic properties of 1 do not match the data reported for the natural product. At this time there is insufficient information available to enable a structure reassignment. During the optimization of the Suzuki-Miyaura coupling, an unprecedented biaryl coupling ortho to the borono group was observed. The scope of this unusual reaction has been investigated.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: ■ Experimental Sectionmentioning

confidence: 99%

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What Is the Structure of the Antitubercular Natural Product Eucapsitrione?

et al. 2017

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“…The crucial cyclization can mechanistically be regarded as an intramolecular nucleophilic displacement of the methoxy group to afford a keto ester 13 with about 55 % yield (Scheme 5). Only a few nucleophilic additions to electron-deficient anthraquinones are known [20,24,25] and intramolecular reactions of this type are more facile [21,[26][27][28][29][30]. The subsequent ethoxydecarbonylation under acidic conditions to yield ketone 14 presented no problem.…”

Section: Nucleophilic Reactionsmentioning

confidence: 99%

Angucyclines: Total syntheses, new structures, and biosynthetic studies of an emerging new class of antibiotics

Krohn

Rohr

1997

Topics in Current Chemistry

182

150

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General and recent aspects of chemical syntheses on angucyclinones and selected related natural products are summarized here. In the first part of this review on angucyclines, the chemical reaction used as a key step for the construction of the angucyclinone frame is discussed. In the second part, new members of the angucycline group of antibiotics, their bioactivity and recent biosynthetic studies including modern aspects of molecular biology (genetics) are reviewed.

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TheMitsunobu Reaction

1992

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Alkyl and aryl phosphites and phosphines react with compounds having weak heteroatom–heteroatom bonds, such as SS, OO, etc., and with azo compounds to form reactive phosphonium salts. These phosphonium salts in turn promote “redox” condensation reactions with compounds having active hydrogens. The condensation reaction of alcohols using the redox couple of a triaryl‐ or trialkylphosphine and a dialkyl azodicarboxylate has become known as the Mitsunobu reaction, based on his pioneering work in the late 1960s. The overall reaction is summarized, wherein the alcohol (R 1 OH) and acidic compound (H–Nu) are condensed to form product (R 1 –Nu), while triphenylphosphine is oxidized to triphenylphosphine oxide and the azodicarboxylate is reduced to the hydrazine. Although the typical redox combination is diethyl azodicarboxylate (DEAD) and triphenylphosphine, many other combinations have found selected use. The reaction is generally limited to primary and secondary alcohols, although tertiary alcohols react in a few intramolecular and intermolecular reactions. For secondary alcohols the reaction usually proceeds with clean inversion of stereochemistry. The acidic component of the reaction generally has an aqueous p K a < 15, with intramolecular reactions providing the exceptions. Examples of H–Nu include oxygen nucleophiles such as carboxylic acids and phenols; nitrogen nucleophiles such as imides, hydroxamates, and heterocycles; sulfur nucleophiles such as thiols and thioamides; and carbon nucleophiles such as β‐ketoesters. Major reviews of the Mitsunobu reaction were published in 1981 by Mitsunobu and in 1983 by Castro. The former review concentrated on reactions using DEAD/triphenylphosphine, while the latter review focused on reactions in which halogens replaced the hydroxy group using reagents such as triphenylphosphine/carbon tetrachloride, triphenyl phosphite/iodomethane, and triphenylphosphine/ N ‐halosuccinimide. Reactions involving the DEAD/triphenylphosphine redox system are the principal subject of this chapter, with emphasis on the literature between 1981 and 1988.

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Anthraquinone dye intermediates as precursors of aklavinone-type anthracyclinones

Cited by 24 publications

References 20 publications

What Is the Structure of the Antitubercular Natural Product Eucapsitrione?

What Is the Structure of the Antitubercular Natural Product Eucapsitrione?

Angucyclines: Total syntheses, new structures, and biosynthetic studies of an emerging new class of antibiotics

TheMitsunobu Reaction

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