- Total Synthesis of the Natural Products Ulmoside A and (2 R,3 R)-Taxifolin-6- C -β- d -glucopyranoside
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An efficient first total synthesis of highly polar ulmoside A and (2 R,3 R)-taxifolin-6- C -β- d -glucopyranoside, useful for the prevention of metabolic disorders, has been described. Key elements of the synthesis include a Sc(OTf) 3-catalyzed regio- and stereoselective C -glycosidation on taxifolin in 35percent yield with d -glucose and chiral semipreparative reverse-phase high-performance liquid chromatography (HPLC) for the separation of both taxifolins and the diastereomeric mixture of taxifolin-6- C -β- d -glucopyranosides. Correlation of the analytical data of synthetic ulmoside A and its diastereomer with a natural ulmoside A sample confirmed the assigned absolute stereochemistry of the natural products.
- Batchu, Venkateswara Rao,Dorigundla, Aravind Reddy,Gurrapu, Raju,Macha, Lingamurthy,Vanka, Umamaheswara Sarma
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supporting information
p. 1097 - 1101
(2020/07/03)
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- Synthesis of polyprenylated benzoylphloroglucinols by regioselective prenylation of phloroglucinol in an aqueous medium
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Regioselective tri-C-prenylation of phloroglucinol, leading to a compound with gem-disubstitution, has been achieved with prenyl bromide in the presence of potassium hydroxide in an aqueous medium. Geranyl- and isolavandulylphloroglucinol, obtained by ortho-lithiation, were diprenylated under the same conditions. C-Benzoylation of the trialkylated derivatives using benzoyl cyanide in the presence of triethylamine afforded two natural products, grandone and kolanone, and an isomer of weddellianone A. Attemped electrophilic cyclization reactions, aimed at a biomimetic synthesis of polycyclic polyprenylated acylphloroglucinols (PPAPs), are also reported. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Raikar, Sanjay B.,Nuhant, Philippe,Delpech, Bernard,Marazano, Christian
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experimental part
p. 1358 - 1369
(2009/04/04)
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- Synthesis of pelargonidin 3-O-6″-O-acetyl-β-d-glucopyranoside, an acylated anthocyanin, via the corresponding kaempferol glucoside
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The first total synthesis of pelargonidin 3-O-6″-O-acetyl-β-d-glucopyranoside, an acylated anthocyanin of magenta-colored Verbena flowers, was successfully carried out. The key intermediate, protected kaemferol 3-O-glucoside, was constructed by the Baker-
- Oyama, Kin-ichi,Kawaguchi, Satoshi,Yoshida, Kumi,Kondo, Tadao
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p. 6005 - 6009
(2008/02/10)
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- Biomimetic total synthesis of gambogin and rate acceleration of pericyclic reactions in aqueous media
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A significant rate acceleration of a Claisen rearrangement and of a Claisen/Diels-Alder reaction cascade sequence was observed in the presence of water. This reaction sequence was used in a total synthesis of gambogin (1) from a tricyclic dialkene 3 via 2
- Nicolaou,Xu, Hao,Wartmann, Markus
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p. 756 - 761
(2007/10/03)
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- First synthesis of antimalarial Machaeriols A and B
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A short and efficient synthesis of the naturally occurring antimalarial compounds, Machaeriols A and B, from commercially available citronellal via hetero-Diels-Alder cycloaddition and Suzuki coupling in 33% overall yield is described.
- Chittiboyina, Amar G.,Reddy, Ch. Raji,Watkins, E. Blake,Avery, Mitchell A.
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p. 1689 - 1691
(2007/10/03)
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- The first direct synthesis of α-mangostin, a potent inhibitor of the acidic sphingomyelinase
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A total synthesis of α-mangostin 1a has been achieved. The key cyclization reaction to construct the xanthone framework was undertaken by employing the PPh3-CCl4 conditions. The inhibitory activities of 1a and the benzophenone intermediate 16 against the acidic sphingomyelinase were discussed.
- Iikubo, Kazuhiko,Ishikawa, Yuichi,Ando, Noritaka,Umezawa, Kazuo,Nishiyama, Shigeru
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p. 291 - 293
(2007/10/03)
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