The Synthesis of Radermachol

Joshi, B. S.; Jiang, Quingping; Rho, Taikyun; Pelletier, S. William

doi:10.1021/jo00105a046

Cited by 30 publications

(20 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Radiolysis of concentrated H 2 SO 4 solutions is known to produce sulfate radical anion which causes one-electron oxidation of solutes (Equation 3). [30][31][32][33][34] THQ produced transient absorption spectrum with maxima at 340 nm and 440 nm in de-aerated 33 % v/v H 2 SO 4 solution but the absorption maxima at~510 nm has not been observed. The same absorption maxima (340 nm and 440 nm) have been found in corrected absorption spectra of transients in de-aerated 33 % v/v H 2 SO 4 medium ( Figure 5).…”

Section: Resultsmentioning

confidence: 99%

Free Radical Scavenging Reactions of Tetrahydroxyquinone: A Pulse Radiolysis Study

Joshi

2016

ChemistrySelect

View full text Add to dashboard Cite

Free radical induced redox reaction kinetics and mechanism of tetrahydroxy‐1,4‐benzoquinone (THQ) has been studied using pulse radiolysis technique. THQ efficiently scavenged hydrated electron, superoxide radical anion, ethanol radical, hydroxyl radical, azidyl radical, thiocyanate radical anion, sulfate radical anion, haloperoxyl radical, lipid peroxyl radical, tryptophanyl radical and tyrosyl radical. Transient absorption spectra of THQ semiquinone radical anion, THQ radical cation and THQ radical produced with these free radicals and rate constants for these reactions have been studied. A probable mechanism of free radical induced redox reactions of THQ has been proposed. Reaction of THQ with free radicals and cyclic voltammetry measurements suggest its oxidation potentials at 0.81 V and 0.94 V vs NHE. To the best of our knowledge, free radical reactions of THQ have been reported for the first time.

show abstract

Section: Resultsmentioning

confidence: 99%

Free Radical Scavenging Reactions of Tetrahydroxyquinone: A Pulse Radiolysis Study

Joshi

2016

ChemistrySelect

View full text Add to dashboard Cite

show abstract

“…The acetal 49, as a starting material, is available in a 34% overall yield from 1-hydroxynaphthalene in six steps. 35 Lithium-bromine exchange and condensation of the transient anion with an aldehyde afforded alcohols 50. These compounds 50 were used without purification in the next step.…”

Section: Acid-induced Cyclization (B)mentioning

confidence: 99%

A Survey of Synthetic Routes towards the Pyranonaphthoquinone Antibiotic Pentalongin and Syntheses of the Corresponding Nitrogen Derivatives

Claessens¹,

Verniest²,

Jacobs³

et al. 2007

Synlett

View full text Add to dashboard Cite

A survey through the synthetic possibilities of pentalongin and its derivatives is presented. Pentalongin is the parent compound in the 3,4-dehydropyranonaphthoquinone series and is the active principle of the medicinal plant Pentas longiflora. Attention is paid to eight approaches towards these 3,4-dehydropyranonaphthoquinones. Synthetic methodologies for the corresponding nitrogen analogues are described, focusing on several natural products.

show abstract

“…Surprisingly, a literature survey revealed only a single example of such reaction. In an attempt to synthesize a natural product, 24 Joshi et al tried a [2C2] cycloaddition between 3-acetoxyindenone and a protected quinone. Instead of the expected adduct, they isolated after UV irradiation an indenone dimer, which was characterized by X-ray diffraction.…”

Section: -Arylindenones [2c2] Photodimerizationmentioning

confidence: 99%