Results 151 to 160 of about 796 (189)
Some of the next articles are maybe not open access.
Depsidone synthesis. IV. Caloploicin
Australian Journal of Chemistry, 1976The synthesis of the lichen depsidone caloploicin (2,4,7-trichloro-3-hydroxy-8-methoxy-1,6,9- trimethyldibenzo[b,e][l,4]dioxepin-11-one) (1) by oxidative coupling of 5'-chloro-2,2',4-trihydroxy-4- methoxy-3',6,6'-trimethylbenzophenone (23), and subsequent steps, is described.
MV Sargent, P Vogel
openaire +1 more source
Chemischer Informationsdienst, 1981
AbstractOxidative Kupplung der substituierten 2,2′‐Dihydroxy‐4‐methoxy‐benzophenone (I), (IV) bzw. (VII) mit K3 [Fe(CN)6] unter optimalen Bedingungen liefert die Grisadiendione (II), (V) bzw. (VIII), die sich bei Thermolyse in fester Form oder in Lösungsmitteln wie TFA/ CHz C12, Diphenylether oder Phenetol in die Depsidone (III), (VI) bzw.
T. SALA, M. V. SARGENT
openaire +1 more source
AbstractOxidative Kupplung der substituierten 2,2′‐Dihydroxy‐4‐methoxy‐benzophenone (I), (IV) bzw. (VII) mit K3 [Fe(CN)6] unter optimalen Bedingungen liefert die Grisadiendione (II), (V) bzw. (VIII), die sich bei Thermolyse in fester Form oder in Lösungsmitteln wie TFA/ CHz C12, Diphenylether oder Phenetol in die Depsidone (III), (VI) bzw.
T. SALA, M. V. SARGENT
openaire +1 more source
J. Chem. Soc., Perkin Trans. 1, 1981
The synthesis of a number of grisa-3′,5′-diene-2′,3-diones by oxidative coupling of substituted 2,2′-dihydroxy-4-methoxybenzophenones is described. The rearrangement of these grisadienediones to depsidones under basic, acidic, and thermal conditions is described and the mechanisms of these reactions are discussed.
Tony Sala, Melvyn V. Sargent
openaire +1 more source
The synthesis of a number of grisa-3′,5′-diene-2′,3-diones by oxidative coupling of substituted 2,2′-dihydroxy-4-methoxybenzophenones is described. The rearrangement of these grisadienediones to depsidones under basic, acidic, and thermal conditions is described and the mechanisms of these reactions are discussed.
Tony Sala, Melvyn V. Sargent
openaire +1 more source
Chemischer Informationsdienst, 1978
AbstractAusgehend von Oxo‐sulfon (Ia) wird sukzessiv über die angegebenen Stufen das Benzophenon (VIIb) synthetisiert, aus dem durch oxidative Kupplungsreaktion und nachfolgende Debromierung Tridechlordihydro‐nidulin (VIIIb) gewonnen wird.
P. DJURA, M. V. SARGENT
openaire +1 more source
AbstractAusgehend von Oxo‐sulfon (Ia) wird sukzessiv über die angegebenen Stufen das Benzophenon (VIIb) synthetisiert, aus dem durch oxidative Kupplungsreaktion und nachfolgende Debromierung Tridechlordihydro‐nidulin (VIIIb) gewonnen wird.
P. DJURA, M. V. SARGENT
openaire +1 more source
Depsidone synthesis. III. Grayanic acid
Australian Journal of Chemistry, 1976The structure of the lichen depsidone grayanic acid (1) (6-heptyl-8-hydroxy-3-methoxy-1-methyl-11- oxo-11 H -dibenzo[b,e][1,4]dioxepin-7-carboxylic acid) proposed by Shibata and Chiang was confirmed by the synthesis firstly of methyl O -methylgrayanate (19), and then of grayanic acid itself. The key step in both syntheses was an Ullmann reaction.
P Djura, MV Sargent
openaire +1 more source
Bioactive Depsidones from the Fungus Pilobolus heterosporus
Planta Medica, 2014A new aromatic ester, pilobolusate (1), four new depsidones, pilobolusones A-D (2-5), five known depsidones, (6-10), and ergosterol were isolated from the fungus Pilobolus heterosporus. Their structures were established on the basis of spectroscopic data.
Oue-artorn, Rajachan +3 more
openaire +2 more sources
Depsidones and fatty acids of Parmelia stygia
Phytochemistry, 1984Abstract One Russian sample of the lichen Parmelia stygia has yielded fumarprotocetraric acid, while a second contained the same compound accompanied by colensoinic, lobaric, caperatic and norcaperatic acids.
Nataliya P. Mishchenko +3 more
openaire +1 more source
Depsidone synthesis. VI. Colensoic acid
Australian Journal of Chemistry, 1976The synthesis of the lichen depsidone colensoic acid (1) (8-hydroxy-3-methoxy-11-oxo-1,6-dipentyl- 11H-dibenzo[b,e][l,4]dioxepin-7-carboxylic acid) by Ullmann reaction of benzyl-2-bromo-4-methoxy- 6-pentylbenzoate (18) and methyl 4,6-dibenzyloxy-3-hydroxy-2-pentylbenzoate (27) and subsequent steps is described.
P Djura, MV Sargent
openaire +2 more sources
New depsidones from Lobaria oregana
Phytochemistry, 1980Abstract From the lichen, Lobaria oregana , two new minor metabolises, methylstictic acid ( 4 ) and cryptostictic acid ( 5 ) were isolated. The structures of 4 and 5 were elucidated by 1 H NMR and MS analysis.
Sachiko Shimada (née Miyoshi) +3 more
openaire +1 more source
A new depsidone from Usnea diffracta
Chinese Chemical Letters, 2009Abstract A new depsidone, diffractione A ( 1 ), as well as six known phenolic compounds ( 2 – 7 ) were isolated from Usnea diffracta . Their structures were elucidated by 1D and 2D NMR spectroscopy together with HRESIMS analysis. All components were obtained for the first time from U. diffracta.
Huan Yang Qi +2 more
openaire +1 more source