Novel Benzotropolone and 2H-Furo[3,2-b]benzopyran-2-one Pigments fromTricholoma aurantium (Agaricales)

@article{Klostermeyer2000NovelBA,
  title={Novel Benzotropolone and 2H-Furo[3,2-b]benzopyran-2-one Pigments fromTricholoma aurantium (Agaricales)},
  author={D{\"o}rte Klostermeyer and Liliana Knops and Tilman Sindlinger and Kurt Polborn and Wolfgang Steglich},
  journal={European Journal of Organic Chemistry},
  year={2000},
  volume={2000},
  pages={603-609}
}
The bright orange-red color of the toadstool Tricholoma aurantium is due to the benzotropolone pigment aurantricholone (1). The compound is at least partially present as the calcium salt. Minor pigments are the yellow 2H-furo[3,2-b]benzopyran-2-one derivatives aurantricholides A (7a) and B (7b), which exhibit strong green fluorescences. Their structures have been established by total syntheses. 
Syntheses of 3,4-benzotropolones by ring-closing metatheses.
TLDR
Hydrolysis of the dimethyl ketal moiety and enolization provided the 3,4-benzotropolones and this access comprises 4-6 steps and totaled a 22-81% yield.
Structural Revision and Biomimetic Synthesis of Goupiolone B.
TLDR
In this study, the structure of goupiolone B was revised on the basis of DFT calculations of the 13 C NMR chemical shifts and biosynthetic considerations and it was suggested that the compound was produced by oxidative coupling between catechol and goupiola, which was strongly supported by biomimetic synthesis.
1. Tetronic Acids
Tetronic acids belong to the class of 4-hydroxybutenolides that are characterized by a 4-hydroxy-2(5H)-furanone ring, as it can be seen in the generic structure of Scheme 1.1 [1]. This type of
Regioselective Bromination of Benzocycloheptadienones for the Synthesis of Substituted 3,4-Benzotropolones Including Goupiolone A.
TLDR
Coupling with excess phenylboronic acid and ketal hydrolysis provided the diphenylated benzotropolone 56 and suggests a strategy, by which the natural bispulvinone aurantricholone might be reached.
Secondary Metabolites Isolated from Tricholoma Species (Basidiomycota, Tricholomatacee): A Review
TLDR
This review is the first complete report about the secondary metabolites isolated to date from the fruiting bodies of Tricholoma (Fr.) Staude, with the exclusion of most volatile constituents.
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Zur Kenntnis der o‐Chinone, XXIV. Synthese, Struktur und Eigenschaften von 1′.2′‐Dihydroxy‐6.7‐benzotropolonen
1′.2′-Dihydroxy-benzotropolon-Derivate konnen nach zwei Methoden dargestellt werden: 1.aus 3 Moll. eines o-Benzochinons mit unsubstituierter Doppelbindung und 1 Mol. eines geeigneten
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