- The first asymmetric total synthesis of several 3,4-dihydroxy-2,2-dimethyl- chroman derivatives
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The stereoisomers of 3,4-dihydroxy-6-methoxy-2,2-dimethyl-chroman 1a-c and 3,4,7-trihydroxy-6-acetyl-2,2-dimethyl-chroman 2a-c were conveniently prepared for the first time via a synthesis in which Sharpless asymmetric dihydroxylation and Jacobsen's catalytic asymmetric epoxidation are the key steps.
- Wang, Qiaoling,She, Xuegong,Ren, Xinfeng,Ma, Junying,Pan, Xinfu
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- Synthesis and evaluation of 2,2-dimethylchroman derivatives as inhibitors of ICAM-1 expression on human endothelial cells
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We herein report the synthesis of novel 2,2-dimethylchroman analogs and their effect on the modulation of tumor necrosis factor-α-induced expression of intercellular adhesion molecule-1 in human endothelial cells. These compounds were found to be potent i
- Dhawan, Ashish,Balwani, Sakshi,Prasad, Ashok K.,Ghosh, Balaram,Parmar, Virinder S.
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- 6-hydroxy-2,2-dimethyl-3,4-dihydro-2H-benzo[b]pyran
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The title compound, 2,2-dimethylchroman-6-ol, C11H14O2, has been identified as a side product from the condensation of hydroquinone with 2-methylbut-3-en-2-ol. The pyran ring has a half-chair conformation. The hydroxyl groups are involved in intermolecular hydrogen bonding which generates infinite spiral chains around the fourfold screw axes; the O...O hydrogen-bonded distances are 2.661 (1) angstrom.
- Jha, Amitabh,Malhotra, Sanjay,Parmar, Virinder S.,Errington, William
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- Redox inactivation of human 15-lipoxygenase by marine-derived meroditerpenes and synthetic chromanes: Archetypes for a unique class of selective and recyclable inhibitors
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The selective inhibition of human 15-lipoxygenase (15-hLO) could serve as a promising therapeutic target for the prevention of atherosclerosis. A screening of marine sponges revealed that crude extracts of Psammocinia sp. exhibited potent 15-hLO inhibitory activity. Bioassay-guided fractionation led to the isolation of chromarols A-E (8-12) as potent and selective inhibitors of 15-hLO. An additional 22 structurally related compounds, including meroditerpenes from the same Psammocinia sp. (3, 4, 13-16) and our pure compound repository (17, 18), commercially available tocopherols (19-24), and synthetic chromanes (25-32), were evaluated for their ability to inhibit human lipoxygenases. The 6-hydroxychromane moiety found in chromarols A-D was identified as essential for the selective redox inhibition of 15-hLO. Furthermore, the oxidized form of the 6-hydroxychromane could be reduced by ascorbate, suggesting a potential regeneration pathway for these inhibitors in the body. This pharmacophore represents a promising paradigm for the development of a unique class of recyclable 15-hLO redox inhibitors for the treatment of atherosclerosis.
- Cichewicz, Robert H.,Kenyon, Victor A.,Whitman, Stephanie,Morales, Nancy M.,Arguello, Joanne F.,Holman, Theodore R.,Crews, Phillip
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- Versatile synthesis of benzopyrans via ortho-Claisen rearrangement of allyl ethers
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Benzopyrans can be efficiently synthesized by reacting a phenol and an allylic alcohol in a trifluoroacetic acid/water mixture under argon at room temperature. The procedure is widely applicable and allows benzopyrans to be synthesized rapidly.
- Ismail, Fyaz M. D.,Hilton, Mark J.,Stefmovic, Marijan
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- Magnesium dicarboxylates promote the prenylation of phenolics that is extended to the total synthesis of icaritin
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The prenylation of phenolic substrates promoted by magnesium dicarboxylates was developed. An investigation of the scope demonstrated that substrates with electron-donating group(s) gave better yields than those with electron-withdrawing group(s). Althoug
- Fu, Xuewen,Lu, Xiaoxia,Wang, Chun,Wen, Yongju,Xiong, Wei,Zhang, Guolin,Zhang, Jichao
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p. 1117 - 1124
(2022/02/16)
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- NOVEL USE OF SUBSTITUTED CHROMAN-6-OLS
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The present invention is directed towards the use of substituted chroman-6-ols of formula (I) wherein R1 and R2 are independently from each other H or C1-11-alkyl or (CH2)n—OH with n being an integer
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Paragraph 0177-0179
(2021/02/05)
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- PROCESS FOR THE MANUFACTURE OF CHROMAN-6-OLS WITH SHORT SIDE CHAINS
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The present invention is directed to a process for the manufacture of a compound of formula (III), comprising the step of reacting a compound of formula (I) with a compound of formula (IIA), (IIB) or (IIC) in the presence of an acid catalyst and in a mixture of two solvents, wherein OR is OH, acetate, methanoate, propionate, butyrate or benzoate, A is CH2, R1 is C1-5-alkyl, R2 is either H or C1-2-alkyl, R4 is either H or C1-4-alkoxy or C1-4-alkyl, R3 and R5 are independently from each other either H or C1-4-alkyl, and the first of the two solvents is water, and the second of the two solvents is selected from aliphatic C5-8-hydrocarbons, cycloaliphatic C5-8-hydrocarbons, dialkyl ethers and methyl-substituted benzenes and any mixture thereof.
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Page/Page column 10-15
(2019/10/23)
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- Synthesis and antitumor activity evaluation of compounds based on toluquinol
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Encouraged by the promising antitumoral, antiangiogenic, and antilymphangiogenic properties of toluquinol, a set of analogues of this natural product of marine origin was synthesized to explore and evaluate the effects of structural modifications on their cytotoxic activity. We decided to investigate the effects of the substitution of the methyl group by other groups, the introduction of a second substituent, the relative position of the substituents, and the oxidation state. A set of analogues of 2-substituted, 2,3-disubstituted, and 2,6-disubstituted derived from hydroquinone were synthesized. The results revealed that the cytotoxic activity of this family of compounds could rely on the hydroquinone/benzoquinone part of the molecule, whereas the substituents might modulate the interaction of the molecule with their targets, changing either its activity or its selectivity. The methyl group is relevant for the cytotoxicity of toluquinol, since its replacement by other groups resulted in a significant loss of activity, and in general the introduction of a second substituent, preferentially in the para position with respect to the methyl group, was well tolerated. These findings provide guidance for the design of new toluquinol analogues with potentially better pharmacological properties.
- Cheng-Sánchez, Iván,Torres-Vargas, José A.,Martínez-Poveda, Beatriz,Guerrero-Vásquez, Guillermo A.,Medina, Miguel ángel,Sarabia, Francisco,Quesada, Ana R.
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- Alkylation of Phenol And Hydroquinone by Prenol in the Presence of Organoaluminum Catalysts
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Prenylphenols and 2,2-dimethylbenzopyrans were synthesized via alkylation of phenol and hydroquinone with prenol in the presence of organoaluminum catalysts, i.e., aluminum phenoxide and isopropoxide. Reaction products were isolated and characterized. Sev
- Chukicheva, I. Yu.,Fedorova,Koroleva,Kuchin
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- SUBSTITUTED BENZOXAZOLES AND METHODS OF USE THEREOF
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The invention provides compounds having the general formula (I): and pharmaceutically acceptable salts thereof, wherein the variables RA, subscript n, ring A, X2, L, subscript m, X1, R1, R2, R3, Rsup
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Page/Page column 82; 83
(2014/09/29)
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- Molecular iodine catalyst promoted synthesis of chromans and 4-aryl-3,4-dihydrobenzopyran-2-ones via [3+3] cyclocoupling
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Molecular iodine as an inexpensive catalyst is described in the construction of 2-substituted or 2,2-disubstituted chromans and 4-aryl-3,4-dihydrobenzopyran-2-ones via [3+3] cyclocoupling. For the synthesis of chromans, phenols and allylic alcohols were refluxed in chloroform in presence of 20 mol % I2 while [3+3] cyclocoupling of phenols and cinnamic acids proceeded to give 4-aryl-3,4-dihydrobenzopyran-2-ones using 30 mol % I2. Later reaction occurs via a tandem hydroarylation- esterification process at 120-130°C under solvent free conditions. Chromans were obtained in 20-92% yields and substituted 4-aryl-3,4-dihydrobenzopyran-2- ones were obtained in 5-85% yields.
- Naik, Mayuri M.,Kamat, Durga P.,Tilve, Santosh G.,Kamat, Vijayendra P.
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p. 5221 - 5233
(2014/07/08)
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- Molecular iodine catalyst promoted synthesis of chromans and 4-aryl-3,4-dihydrobenzopyran-2-ones via [3+3] cyclocoupling
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Molecular iodine as an inexpensive catalyst is described in the construction of 2-substituted or 2,2-disubstituted chromans and 4-aryl-3,4-dihydrobenzopyran-2-ones via [3+3] cyclocoupling. For the synthesis of chromans, phenols and allylic alcohols were refluxed in chloroform in presence of 20 mol % I2while [3+3] cyclocoupling of phenols and cinnamic acids proceeded to give 4-aryl-3,4-dihydrobenzopyran-2-ones using 30 mol % I2. Later reaction occurs via a tandem hydroarylation-esterification process at 120-130 °C under solvent free conditions. Chromans were obtained in 20-92% yields and substituted 4-aryl-3,4-dihydrobenzopyran-2-ones were obtained in 5-85% yields.
- Naik, Mayuri M.,Kamat, Durga P.,Tilve, Santosh G.,Kamat, Vijayendra P.
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p. 5221 - 5233
(2014/12/10)
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- InIII-catalysed tandem C-C and C-O bond formation between phenols and allylic acetates
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Indium triflate catalysed tandem allylation-intramolecular hydroalkoxylation was efficiently carried out by using 1 mol-% of the catalyst under mild conditions to afford the dihydrobenzopyran ring system (chroman-type structure) in good yields. Kinetic, mechanistic and theoretical studies are also presented. Tandem allylation-intramolecular hydroalkoxylation carried out in the presence of an indium catalyst (1 mol-%) under mild conditions provides the dihydrobenzopyranring system in good yields. Kinetic, mechanistic and theoretical studies are presented.
- Vece, Vito,Ricci, Jeremy,Poulain-Martini, Sophie,Nava, Paola,Carissan, Yannick,Humbel, Stephane,Dunach, Elisabet
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supporting information; experimental part
p. 6239 - 6248
(2010/12/29)
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- Investigation into phenoxonium cations produced during the electrochemical oxidation of chroman-6-ol and dihydrobenzofuran-5-ol substituted compounds
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(Chemical Equation Presented) A series of chroman-6-ol and dihydrobenzofuran-5-ol based compounds with structures similar to vitamin E were examined by cyclic voltammetry and controlled potential electrolysis. The compounds displayed characteristic voltammetric features that enabled their electrochemical behavior to be interpreted in relation to the oxidation mechanism for vitamin E. The electrochemical experiments indicated the presence of several oxidized species: cation radicals, phenoxyl radicals, phenoxonium ions, hemiketals, and p-quinones, whose lifetimes varied depending on the extent of methylation of the aromatic ring (R1, R2, R3) and the nature of substituents R4 and R5.
- Hong, Mei Peng,Webster, Richard D.
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p. 2169 - 2175
(2008/09/19)
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- Reaction between phenols and isoprene under zeolite catalysis. Highly selective synthesis of chromans and o-isopentenylphenols
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Chromans 3 and o-isopentenylphenols 4 are synthesized in satisfactory to good yields and selectivities by the reaction of phenols and isoprene in the presence of the commercially available acid faujasite zeolite HSZ-360.
- Bigi, Franca,Carloni, Silvia,Maggi, Raimondo,Muchetti, Chiara,Rastelli, Massimo,Sartori, Giovanni
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p. 301 - 304
(2007/10/03)
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- Acid-Induced Broadening of 1H N.M.R. Signals in the 6-Hydroxychroman and 5-Hydroxydihydrobenzofuran Series
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Acids at least as strong as trichloroacetic acid induce line broadening in the 1H n.m.r. spectra of 6-hydroxychroman and 5-hydroxy-2,3-dihydrobenzofuran derivatives.The effect is specific for derivatives of hydroquinone although it is a weak in the absenc
- Al-Khayat, Isam,Dean, Francis M.,France, Steven N.,Matkin, David A.,Orabi, Mohamed O. A.,et al.
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p. 1301 - 1310
(2007/10/02)
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- Acid-catalysed Condensation of Isoprene with Phenols. Formation of 2,2-Dimethylchromans
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A novel method of nuclear isopentenylation which gives exclusively 2,2-dimethylchromans has been achieved by the direct condensation of phenols, viz. resorcinol, quinol, pyrogallol, and phloroglucinol, with 2-methylbuta-1,3-diene (isoprene) in the presence of orthophosphoric acid as catalyst.Condensation of 2-methylbut-3-en-2-ol with phenols in the presence of aqueous citric acid has been reinvestigated.
- Ahluwalia, Vinod K.,Arora, Krishnan K.,Jolly, Ravinder S.
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p. 335 - 338
(2007/10/02)
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