- Biomimetic formation of 2-tropolones by dioxygenase-catalysed ring expansion of substituted 2,4-cyclohexadienones
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Substituted 2-tropolone natural products are found in plants and fungi. Their biosynthesis is thought to occur by ring expansion from a cyclohexadienone precursor, but this reaction has not previously been demonstrated experimentally. Treatment of 6-hydroxy-6-hydroxymethylcyclohexa-2,4-dienone with the non-haem iron(II)-dependent extradiol catechol dioxygenase MhpB from Escherichia coli results in the formation of the 2-tropolone ring-expansion product through a pinacol-type rearrangement. Three further substituted cyclohexa-2,4-dienone analogues were prepared, and treatment of each analogue was found to give the substituted 2-tropolone ring-expansion product. This ring expansion could also be effected nonenzymatically by treatment with 1,4,7-triazacyclononane and FeCl2. This is a novel transformation for non-haem iron-dependent enzymes, and this is the first experimental demonstration of the proposed ring-expansion reaction in tropolone biosynthesis.
- Xin, Meite,Bugg, Timothy D. H.
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- A VERSATILE NEW STRATEGY FOR THE SYNTHESIS OF TROPOLONES
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Swern-type oxidation of various 7-halogenobicycloheptane-2,3- or -3,4-diols affords the corresponding bicyclic diketones which undergo in situ ring expansion and loss of hydrogen halide to give α-tropolones in high yield.The quantitative conversion of the isolable 1,4-diketone 26 into the γ-tropolone acetate 27 has been achieved.
- Banwell, Martin G.,Onrust, Rene
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- TROPOLONE DERIVATIVES AND TAUTOMERS THEREOF FOR IRON REGULATION IN ANIMALS
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Disclosed are a series of compounds or their tautomers having a general structure represented by Formula (la), (lb), (Ila), (lIb), or (lIc) and pharmaceutically acceptable salts thereof. The present disclosure also relates to pharmaceutical compositions comprising said compounds or tautomers. The present disclosure further relates to a method of treating a disease or condition associated with iron dysregulation or dysfunctional iron homeostasis comprising administering to a subject in need thereof a therapeutically effective amount of Formula (la), (lb), (Ila), (lIb), or (lIc) compounds or tautomers.
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