58879-34-8Relevant articles and documents
A Reverse Approach to the Total Synthesis of Halichondrin B
Nicolaou,Pan, Saiyong,Shelke, Yogesh,Das, Dipendu,Ye, Qiuji,Lu, Yong,Sau, Susanta,Bao, Ruiyang,Rigol, Stephan
supporting information, p. 9267 - 9276 (2021/07/01)
A new strategy is described for the total synthesis of halichondrin B featuring reversal of the sequential construction of a number of its cyclic ethers from the classical approach by instead forming C-O bonds first followed by C-C bond formation. Employing the Nicholas reaction to generate linear ethers as precursors for the total synthesis of halichondrin B and other members of the halichondrin and eribulin families of compounds, this novel approach provides new opportunities for the development of improved syntheses of these complex and valuable compounds. In this Article, we report the syntheses of defined fragments I, MN, EFG, and A. Fragments I and MN were then coupled and elaborated to advanced intermediate IJKLMN, which was joined with fragment EFG to afford, after appropriate elaboration and macrolactonization, the more advanced polycyclic intermediate EFGHIJKLMN. Elaboration of the latter and coupling with fragment A followed by further functionalization completed the total synthesis of halichondrin B through a short and convergent pathway.
Palladium-Catalyzed Atom-Transfer Radical Cyclization at Remote Unactivated C(sp3)?H Sites: Hydrogen-Atom Transfer of Hybrid Vinyl Palladium Radical Intermediates
Ratushnyy, Maxim,Parasram, Marvin,Wang, Yang,Gevorgyan, Vladimir
, p. 2712 - 2715 (2018/03/02)
A novel mild, visible-light-induced palladium-catalyzed hydrogen atom translocation/atom-transfer radical cyclization (HAT/ATRC) cascade has been developed. This protocol involves a 1,5-HAT process of previously unknown hybrid vinyl palladium radical intermediates, thus leading to iodomethyl carbo- and heterocyclic structures.
METHOD FOR SYNTHESIZING A PRECURSOR OF A SINGLE DAIRY-LACTONE ISOMER
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Paragraph 0045; 0065; 0066, (2018/03/25)
This disclosure provides a method for preparing a precursor of a single dairy-lactone isomer, methods of preparing a single dairy-lactone isomer, and to the organoleptic uses thereof.
Chiral hypervalent iodine(III) catalyst promotes highly enantioselective sulfonyl-and phosphoryl-oxylactonizations
Gelis, Coralie,Dumoulin, Audrey,Bekkaye, Mathieu,Neuville, Luc,Masson, Géraldine
, p. 278 - 281 (2017/11/27)
An efficient enantioselective hypervalent iodine promoted oxylactonization of 4-pentenoic acids has been achieved using stoichiometric or a catalytic amount of chiral aryl-λ3-iodane. This reaction provides straightforward access to a wide range of sulfonyloxy-and phosphoryloxy-γ-butyrolactones in respectable yields with moderate to excellent enantioselectivities.
HETEROCYCLIC COMPOUNDS AND THEIR USE AS RETINOID-RELATED ORPHAN RECEPTOR (ROR) GAMMA-T INHIBITORS
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Paragraph 0346, (2016/01/25)
Provided are heterocyclic compounds having a RORγt inhibitory action represented by the formula (I): wherein each symbol is as defined in the specification, or a salt thereof.
Chemo-enzymatic synthesis of chiral epoxides ethyl and methyl (S)-3-(Oxiran-2-yl)propanoates from Renewable levoglucosenone: An access to enantiopure (S)-dairy lactone
Peru, Aurélien A. M.,Flourat, Amandine L.,Gunawan, Christian,Raverty, Warwick,Jevric, Martyn,Greatrex, Ben W.,Allais, Florent
, (2016/08/12)
Chiral epoxides-such as ethyl and methyl (S)-3-(oxiran-2-yl)propanoates ((S)-1a/1b)-are valuable precursors in many chemical syntheses. Until recently, these compounds were synthesized from glutamic acid in four steps (deamination, reduction, tosylation and epoxide formation) in low to moderate overall yield (20%-50%). Moreover, this procedure requires some harmful reagents such as sodium nitrite ((eco)toxic) and borane (carcinogen). Herein, starting from levoglucosenone (LGO), a biobased chiral compound obtained through the flash pyrolysis of acidified cellulose, we propose a safer and more sustainable chemo-enzymatic synthetic pathway involving lipase-mediated Baeyer-Villiger oxidation, palladium-catalyzed hydrogenation, tosylation and treatment with sodium ethoxide/methoxide as key steps. This route afforded ethyl and methyl (S)-3-(oxiran-2-yl)propanoates in 57% overall yield, respectively. To demonstrate the potentiality of this new synthetic pathway from LGO, the synthesis of high value-added (S)-dairy lactone was undertaken from these epoxides and provided the target in 37% overall yield from LGO.
PYRIMIDINE AND TRIAZINE DERIVATIVES AND THEIR USE AS AXL INHIBITORS
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Page/Page column 95, (2016/07/05)
Compounds of the general formula(I): (I) processes for the preparation of these compounds, compositions containing these compounds, and the uses of these compounds.
PYRAZOLE AMIDE DERIVATIVE
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Page/Page column 91; 92, (2015/09/28)
The present invention relates to a novel compound having a function of inhibiting RORγ activity. The present invention also relates to pharmaceutical composition comprising the compound, a use of the compound in treating or preventing autoimmune diseases, inflammatory diseases, metabolic diseases, or cancer diseases.
Stereochemical elucidation of streptorubin B
Haynes, Stuart W.,Sydor, Paulina K.,Corre, Christophe,Song, Lijiang,Challis, Gregory L.
, p. 1793 - 1798 (2011/04/12)
Streptorubin B is a structurally remarkable mem-ber of the prodiginine group of antibiotics produced by several actinobacteria, including the model organism Streptomyces coelicolor A3(2). Transannular strain within the pyrrolophane structure of this molecule causes restricted rotation that gives rise to the possibility of (diastereomeric) atropisomers. Neither the relative nor the absolute stereochemistry of streptorubin B is known. NOESY NMR experiments were used to define the relative stereochemistry of the major atropisomer of streptorubin BHCl in solution as anti. We exploited this finding together with our knowledge of streptorubin B biosynthesis in S. coelicolor to determine the absolute stereochemistry of the anti atropisomer. 2-Undecylpyrrole stereoselectively labeled with deuterium at C-4′ was synthesized and fed to a mutant of S. coelicolor, which was unable to produce streptorubin B because it was blocked in 2-undecylpyrrole biosynthesis, and in which the genes responsible for the last two steps of streptorubin B biosynthesis were overexpressed. 1H and 2H NMR analysis of the stereoselectively deuterium-labeled streptorubin BHCl produced by this mutasynthesis strategy allowed us to assign the absolute stereochemistry of the major (anti) atropisomer as 7′S. HPLC analyses of streptorubin B isolated from S. coelicolor on a homochiral stationary phase and comparisons with streptorubin B derived from an enantioselective synthesis showed that the natural product consists of an approximately 88:7:5 mixture of the (7′S, anti), (7′S, syn), and (7′R, anti) stereoisomers.
Synthesis of azide-alkyne fragments for "Click" chemical applications. Part 2. Formation of oligomers from orthogonally protected chiral trialkylsilylhomopropargyl azides and homopropargyl alcohols
Montagnat, Oliver D.,Lessene, Guillaume,Hughes, Andrew B.
scheme or table, p. 390 - 398 (2010/03/30)
(Chemical Equation Presented) A small library of chiral, β3-substituted homopropargyl alcohols and chiral β3-substituted trimethylsilylhomopropargyl azides were generated starting from natural L-amino acids. The free alkynes and azides were then coupled, using a Huisgen 1,3-dipolar cycloaddition, to provide chiral oligomeric 1,4-disubstituted-1,2,3-triazoles as potential peptidomimetic compounds. The work is an extension to the previous synthesis of racemic, orthogonally protected 1,4-disubstituted-1,2,3-triazoles from the corresponding α-substituted propargyl alcohols and α-substituted trialkylsilylpropargyl azides.
