- Total Syntheses of FR-901235, Auxarthrones A-D, and Lamellicolic Anhydride
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In our previous study, an unusual rearrangement reaction was discovered whereby dinaphthyl ketones with three hydroxy groups at restricted positions were transformed into a phenalenone ring and a benzene ring. Using the rearrangement as a key reaction, the first total syntheses of FR-901235 and auxarthrones A-D from an unstable triketone common intermediate are described. Furthermore, lamellicolic anhydride was synthesized from the triketone. This conversion is part of the putative biosynthetic pathway and was achieved experimentally for the first time.
- Kiyotaki, Kotaro,Kayukawa, Takuto,Imayoshi, Ayumi,Tsubaki, Kazunori
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supporting information
p. 9220 - 9224
(2020/11/30)
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- Preparation process of 3,6-dihydroxy-2-naphthaldehyde
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The invention belongs to the field of organic synthesis, and particularly relates to a preparation process of 3,6-dihydroxy-2-naphthaldehyde. The process includes a step 1) of subjecting 2,7-dihydroxynaphthalene to bromination with liquid bromine to form a first compound the structure of which is shown as a formula I; a step 2) of subjecting the first compound to a nucleophilic substitution reaction to generate the 3,6-dihydroxy-2-naphthaldehyde. The process solves a problem that preparation processes in the prior art have long synthesis steps and unsatisfactory yields.
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Paragraph 0024; 0025
(2019/10/01)
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- Introduction of polar groups on the naphthalene scaffold of molecular tongs inhibiting wild-type and mutated HIV-1 protease dimerization
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A new series of naphthalene-based molecular tongs containing polar groups at the 3-position of the naphthalene scaffold was synthesized and its anti-dimerization activity was evaluated against HIV-1 protease. The polar groups were introduced mainly via me
- Fanelli,Ressurrei??o,Dufau,Soulier,Vidu,Tonali,Bernadat,Reboud-Ravaux,Ongeri
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supporting information
p. 719 - 727
(2014/06/10)
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- Nicholas reactions in the construction of cyclohepta[ de ]naphthalenes and cyclohepta[de]naphthalenones. The total synthesis of microstegiol
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The application of the Nicholas reaction chemistry of 2,7-dioxygenated naphthalenes in the synthesis of cyclohepta[de]napthalenes and in the synthesis of (±)-microstegiol (1) is presented. The substitution profile of Nicholas monosubstitution (predominantly C-1) and disubstitution reactions (predominantly 1,6-) on 2,7-dioxygenated napthalenes is reported. Application of a 1,8-dicondensation product and selected C-1 monocondensation products to the construction of cyclohepta[de]naphthalenes by way of ring closing metathesis and intramolecular Friedel-Crafts reactions, respectively, is described. Deprotection of the C-7 oxygen function to the corresponding naphthol allows tautomerization to cyclohepta[de]naphthalene-1-ones upon seven-membered-ring closure in most cases, and replacement of the C-2 oxygen function in the naphthalene by a methyl group ultimately allows the synthesis of (±)-microstegiol.
- Taj, Rafiq A.,Green, James R.
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scheme or table
p. 8258 - 8270
(2011/02/23)
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- ORGANIC COMPOUNDS
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Compounds of the formula are inhibitors of protein tyrosine phosphatases (PTPases) and, thus, may be employed for the treatment of conditions mediated by PTPase activity. The compounds of the present invention may also be employed as inhibitors of other enzymes characterized with a phosphotyrosine binding region such as the SH2 domain. Accordingly, the compounds of formula (I) may be employed for prevention and/or treatment of insulin resistance associated with obesity, glucose intolerance, diabetes mellitus, hypertension and ischemic diseases of the large and small blood vessels, conditions that accompany type-2 diabetes, including hyperlipidemia, hypertriglyceridemia, atherosclerosis, vascular restenosis, irritable bowel syndrome, pancreatitis, adipose cell tumors and carcinomas such as liposarcoma, dyslipidemia, and other disorders where insulin resistance is indicated. In addition, the compounds of the present invention may be employed to treat and/or prevent cancer (such as prostate or breast cancer), osteoporosis, neurodegenerative and infectious diseases, and diseases involving inflammation and the immune system.
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Page/Page column 46
(2010/11/27)
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- A modular route to nonracemic cyclo-NOBINs. Preparation of the parent ligand for homo- and heterogeneous catalysis
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A sequence which combines a nonracemic tether, a naphthyl diol, and an aminonaphthol has been developed leading to the new ligand cyclo-NOBIN, which can easily be mounted onto polystyrene. Opportunities for extending the route to substituted cyclo-NOBINs are also discussed.
- Lipshutz, Bruce H.,Buzard,Olsson, Christina,Noson, Kevin
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p. 4443 - 4449
(2007/10/03)
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- Chiral 1,1'-binaphthyl molecular clefts for the complexation of excitatory amino-acid derivatives
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The complexation of N-benzyloxycarbonyl (Cbz) derivatives of the excitatory amino acids L-aspartic acid (Asp; 1), L-glutamic acid (Glu; 3), and, for the first time, L-kainic acid ((2S,3S,3S)-2-carboxy-4-(1-methylethenyl)pyrrolidine-3-acetic acid; Kai; 5) was studied in CDCl3 with a diversity of chiral receptors consisting of a 1,1'-binaphthyl spacer with (carboxamido)pyridine (CONH(py)) functionality attached to the 6,6'-positions in the major groove. Receptors of type A possess two N-(pyridin-2-yl)carboxamide H-bonding sites (e.g. 7), whereas type B-receptors have two N-(pyridine-6,2-diyl)acetamide residues attached (e.g. 8 and 9). Complexes of excitatory amino-acid derivatives and other, achiral α,ω-dicarboxylic acids with these receptors are primarily stabilized by two sets of C = O... H-N and O-H... N H-bonds. Optically active type-A receptors such as (R)- and (S)-7 showed a preference for the larger Glu derivative, whereas type-B receptors such as (R)- and (S)-8 and (R)- and (S)-9 formed more stable complexes with the smaller Cbz-Asp. To improve the poor enantioselectivity shown by 7-9, additional functionality was introduced at the 7,7'-positions of the 1,1'-binaphthyl spacer, and the nature of the H-bonding sites in the 6,6'-positions was varied. Screening the diversity of new racemic receptors for binding affinity, which had been shown in many examples by Gram to correlate with enantioselectivity, demonstrated that (±)-10 and (±)-11 formed the most stable complexes with dicarboxylic acids, and these receptors were synthesized in enantiomerically pure form. Both are type-B binders and contain additional PhCH2O (10) and MeO (11) groups in the 7,7'-positions. By 1H-NMR binding titrations, the complexation of (R)-and (S)-10 and (R)- and (S)-11 with the excitatory amino-acid derivatives was studied in CDCl3, and association constants K(a) between 103 and 2. 105 l mol-1 were measured for the 1:1 host-guest complexes formed. Whereas both 10 and 11 formed stable complexes, enantioselective binding was limited to the PhCH2O-substituted receptor 10, with the (R)-enantiomer complexing Cbz-Asp by 0.7 kcal mol-1 more tightly than the (S)-enantiomer. The structures of the diastereoisomeric complexes were analyzed in detail by experimental methods (complexation-induced changes in 1H-NMR chemical shifts, 1H{1H} nuclear Overhauser effect (NOE) difference spectroscopy) and computer modeling. These studies established that an unusual variety of interesting aromatic interactions and secondary electrostatic interactions are responsible for both the high binding affinity (-ΔG° up to 7.2 kcal mol-1) and the enantioselection observed with (R)- and (S)-10. In an approach to enhance the enantioselectivity by reducing the conformational flexibility of the 1,1'-binaphthyl spacer, an additional crown-ether binding site was attached to the 2,2'-positions in the minor groove of the type-B receptors (R)- and (S)-48. Both the binding affinity and the enantioselectivity (Δ(ΔG°) up to 0.7 kcal mol-1) in the complexation of the excitatory amino-acid derivatives by (R)- and (S)-48 were not altered upon complexation of Hg(CN)2 at the crown-ether binding site, demonstrating lack of cooperativity between the minor- and major-groove recognition sites.
- Martinborough,Mordasini Denti,Castro,Wyman,Knobler,Diederich
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p. 1037 - 1066
(2007/10/02)
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