- Synthesis, crystal structure, and growth inhibition of human hepatoma cell (HepG2) of polyphenolic compounds based on gallates
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Seven compounds (1-7) based on gallate were synthesized and characterized by elemental analysis, 1H NMR, and MS spectra. 2-(3,5-Dibenzyloxy-4- methoxy)phenyl-2-propanol (6) was a new compound. Methyl 3,5-dihydroxy-4- methoxybenzoate (3), methyl 3,5-dibenzyloxy-4-methoxybenzoate (4), 3,5-dibenzyloxy-4-methoxybenzyl alcohol (5), and compound 6 were structurally determined by single-crystal X-ray diffraction for the first time. Crystallography data for 3: space group P21212 1; a = 4.0750(8) A, b = 7.5880(15) A, c = 29.802(6) A; V = 921.5(3) A3 Z = 4. 4: space group P-1; a = 10.068(2) A b = 10.499(2) A, c = 11.388(2) A; α = 76.84(3)°, β= 66.79(3)°, γ = 64.10(3)°; V = 993.0(3) A3, Z = 2. 5: space group P-1; a = 8.1410(16) A, b = 8.7590(18) A, c = 12.879(3) A; α = 91.66(3)°, β= 94.69(3)°, γ = 91.73(3)°; V = 914.4(3) A3; Z = 2. 6: space group P21/c; a = 5.8100(12) A, b = 15.778(3) A, c = 23.237(5) A; β= 96.09(3)°; V = 2118.1(7) A3; Z = 4. All of the seven compounds were evaluated for the inhibition of growth of human hepatoma (HepG2) cells. Comparison with the positive-control 5-fluorouracil (IC50 51.6 μmol/L), 5 showed stronger cytotoxic activity with an IC50 around 15.3 μmol/L, while IC50 value of 3 was 90.3 μmol/L. The effect of slight structural variations in this series of compounds was found to cause a marked change in their activity against HepG2 cells.
- Xiao, Zhu-Ping,Fang, Rui-Qin,Shi, Lei,Ding, Hui,Xu, Chen,Zhu, Hai-Liang
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- Vanadium-Catalyzed Oxidative Intramolecular Coupling of Tethered Phenols: Formation of Phenol-Dienone Products
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A mild and efficient method for the vanadium-catalyzed intramolecular coupling of tethered free phenols is described. The corresponding phenol-dienone products are prepared directly in good yields with low catalyst loadings. Electronically diverse tethered phenol precursors are well tolerated, and the catalytic method was effectively applied as the key step in syntheses of three natural products and a synthetically useful morphinan alkaloid precursor.
- Gilmartin, Philip H.,Kozlowski, Marisa C.
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supporting information
p. 2914 - 2919
(2020/04/10)
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- Cross-coupling reaction of saccharide-based alkenyl boronic acids with aryl halides: The synthesis of bergenin
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A convenient synthetic pathway enabling D-glucal and D-galactal pinacol boronates to be prepared in good isolated yields was achieved. Both pinacol boronates were tested in a series of cross-coupling reactions under Suzuki-Miyaura cross-coupling conditions to obtain the corresponding aryl, heteroaryl, and alkenyl derivatives in high isolated yields. This methodology was applied to the formal synthesis of the glucopyranoside moiety of papulacandin D and the first total synthesis of bergenin. Building blocks with boron: A convenient synthetic route to D-glucal and D-galactal pinacol boronates was developed, and the boronates were used in cross-coupling reactions to generate the corresponding aryl, heteroaryl, and alkenyl derivatives in high yields (see scheme). This methodology was applied to the formal synthesis of the glucopyranoside moiety of papulacandin D and the total synthesis of bergenin.
- Parkan, Kamil,Pohl, Radek,Kotora, Martin
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supporting information
p. 4414 - 4419
(2014/05/06)
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- Chemistry of opium alkaloids, 45. Improvements in the total synthesis of morphine
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The chiral 1,2,3,4-tetrahydroisoquinoline intermediates in the Price and Beyerman routes to morphine, (+)-(R)-1-(3-hydroxy-4-methoxybenzyl)-6-methoxy- 1,2,3,4-tetrahydroisoquinoline (6) and (+)-(R)-1-(3,5-dibenzyloxy-4- methoxybenzyl)-6-methoxy-1,2,3,4-tetrahydroisoquinoline (5), were prepared in high ee by ruthenium-catalyzed asymmetric transfer hydrogenation of the corresponding imine precursors (Noyori method). The yield of the key raw material in the Beyerman route, 3,5-dibenzyloxy-4-methoxyphenylacetric acid (1), starting from gallic acid methyl ester (7) was improved by a factor of 5 over previously described syntheses. Key steps in the new procedure are the selective formation of methyl 3,5-dihydroxy-4-methoxybenzoate (9) via the 3,5-diacetate and an improved benzylation of the hydroxyl groups in 9.
- Meuzelaar, Gerrit J.,Van Vliet, Michiel C. A.,Maat, Leendert,Sheldon, Roger A.
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p. 2315 - 2321
(2007/10/03)
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- Selective hydroxy group protection of gallic acid
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An efficient procedure allowing selective differentiation of the 4-hydroxy group of methyl gallate was reported.
- Zhu, Jieping,Chastanet, Jacqueline,Beugelmans, Rene
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p. 2479 - 2486
(2007/10/03)
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- Asymmetric Synthesis of (2S,3R) β-(4-F-3-NO2) phenyl Serine, D-(R)-4-methoxy-3,5-Bis tButyldimethylsiloxy Phenylglycine and Their Assemblage to C-O-D Ring of Vancomycin
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The asymmetric synthesis of two appropriately functionalyzed non-proteinogenic amino acids 2 and 3 needed for the total synthesis of vancomycin was described.The assemblage of these amino acids into linear tripeptide followed by biary ether formation via intramolecular SNAr reaction led to the fully functionalized C-O-D ring vancomycin.
- Zhu, Jieping,Bouillon, Jean-Philippe,Singh, Girij Pal,Chastanet, Jacqueline,Beugelmans, Rene
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p. 7081 - 7084
(2007/10/02)
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