On the chemistry of indian orchidaceae plants—II
TL;DR: In this paper, the first natural fluorenone derivatives of Dendrobium gibsonii, namely dengibsin and Dengibsnin, have been assigned 1,5-dihydroxy-7-methoxy-9-fluorenone structures.
About: This article is published in Tetrahedron.The article was published on 1985-01-01. It has received 33 citations till now. The article focuses on the topics: Dendrobium gibsonii & Dimethyl terephthalate.
Citations
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TL;DR: Dimethyl carbonate (DMC) was used as a green organic solvent for photocatalytic synthesis of phenanthrene by using anatase TiO2 as the photocatalyst as discussed by the authors.
Abstract: Dimethyl carbonate (DMC) is here proposed – for the first time – as a green organic solvent for photocatalytic synthesis. In this work, the photocatalytic partial oxidation of phenanthrene in dimethyl carbonate (DMC) by using anatase TiO2 as the photocatalyst is described as paradigmatic example of a green synthetic process starting from polycyclic aromatic hydrocarbons (PAHs). For comparison, the same reaction carried out also in ethanol, 1-propanol or 2-propanol is reported. The use of DMC as the solvent allowed us to achieve 19% and 23% selectivity towards 9-fluorenone and 6H-benzo[c]chromen-6-one, respectively. The proposed approach may represent both a new green synthetic process and an environmentally friendly route to degradation of PAHs.
30 citations
TL;DR: In this article, functionalized fluorenones were prepared by sequential cyclization, cyclization-Suzuki cross-coupling/Friedel-Crafts acylation reactions.
29 citations
TL;DR: Two new fluorenone derivatives denchrysans A and B and one new phenanthrenediglycoside denchryside A were isolated from the herbs of Dendrobium chrysanthum (Orchidaceae).
28 citations
TL;DR: Dendrobium aurantiacum Rchb.f.
28 citations
Cites methods from "On the chemistry of indian orchidac..."
...Subfractions 6/4 (1.2 g) was chromatographed on Sephadex LH-20 column with MeOHe CH2Cl2 (7:3) to provide dengibsin (9, 30 mg) (Talapatra et al., 1985) and dendroflorin (10, 11 mg) (Zhang et al., 2004)....
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Patent•
16 Jun 2010TL;DR: In this paper, the authors proposed a process for preparing substituted and unsubstituted terephthalic acid and carboxylate derivatives with a significant renewable content, where a portion of the starting materials utilized is derived from renewable resources.
Abstract: The present invention relates to novel substituted and unsubstituted terephthalic acid and carboxylate derivatives and products prepared therefrom having a significant renewable content The invention also relates to processes for preparing substituted and unsubstituted terephthalic and carboxylate derivatives thereof wherein a portion of the starting materials utilized is derived from renewable resources The invention also relates to novel cyclohexene based intermediates prepared in these processes and to conversion of these intermediates to substituted and unsubstituted cyclohexane-1,4-dicarboxylates and carboxylate derivatives thereof and novel forms of the resulting products having renewable content The invention also relates to products prepared from substituted and unsubstituted terephthalic acid and carboxylate derivatives thereof derived from starting materials derived from renewable resources
21 citations
References
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TL;DR: The structure of pongaglabol has been established as 5-hydroxyfurano(8,7-4″,5″)flavone on the basis of spectral and chemical evidence.
69 citations
TL;DR: In this paper, the position and relative orientation of OMe groups in methoxyflavones can be inferred from benzene-induced solvent shifts of the OMe resonances, and the authors show that an OMe at C-5 suffers a drastic algebraic decrease in solvent shift upon the introduction of an ortho-OMe group at c-6.
68 citations
TL;DR: In this paper, the synthesis of 1, 3-dimethoxyfluoren-9-ones (7a-f) from ethyl 2-aryl-4, 6-dihydroxybenzoates (4a-d) was described.
Abstract: The synthesis of 1, 3-dimethoxyfluoren-9-ones (7a-f) from ethyl 2-aryl-4, 6-dihydroxybenzoates (4a-d), prepared by the reaction of diketene with ethyl 3-aryl-3-oxopropionates (3a-d), is described. Reaction of diketene with 3a-d in the presence of sodium hydride in tetrahydrofuran gave 4a-d. Methylation of 4a-d with methyl iodide, followed by treatment with alcoholic sodium hydroxide, gave 2-aryl-4, 6-dimethoxybenzoic acids (6a-d). Cyclization of 6a-d with trifluoroacetic anhydride gave 7a-f.
17 citations
Journal Article•
3 citations