2319-57-5Relevant articles and documents
Product Control and Insight into Conversion of C6 Aldose Toward C2, C4 and C6 Alditols in One-Pot Retro-Aldol Condensation and Hydrogenation Processes
Gao, Lou,Hou, Wenrong,Hui, Yingshuang,Tang, Yi,Zhan, Yulu,Zhang, Yahong
, p. 560 - 566 (2021/06/25)
Alcohols have a wide range of applicability, and their functions vary with the carbon numbers. C6 and C4 alditols are alternative of sweetener, as well as significant pharmaceutical and chemical intermediates, which are mainly obtained through the fermentation of microorganism currently. Similarly, as a bulk chemical, C2 alditol plays a decisive role in chemical synthesis. However, among them, few works have been focused on the chemical production of C4 alditol yet due to its difficult accumulation. In this paper, under a static and semi-flowing procedure, we have achieved the product control during the conversion of C6 aldose toward C6 alditol, C4 alditol and C2 alditol, respectively. About C4 alditol yield of 20 % and C4 plus C6 alditols yield of 60 % are acquired in the one-pot conversion via a cascade retro-aldol condensation and hydrogenation process. Furthermore, in the semi-flowing condition, the yield of ethylene glycol is up to 73 % thanks to its low instantaneous concentration.
Selective and Scalable Synthesis of Sugar Alcohols by Homogeneous Asymmetric Hydrogenation of Unprotected Ketoses
Tindall, Daniel J.,Mader, Steffen,Kindler, Alois,Rominger, Frank,Hashmi, A. Stephen K.,Schaub, Thomas
supporting information, p. 721 - 725 (2020/10/19)
Sugar alcohols are of great importance for the food industry and are promising building blocks for bio-based polymers. Industrially, they are produced by heterogeneous hydrogenation of sugars with H2, usually with none to low stereoselectivities. Now, we present a homogeneous system based on commercially available components, which not only increases the overall yield, but also allows a wide range of unprotected ketoses to be diastereoselectively hydrogenated. Furthermore, the system is reliable on a multi-gram scale allowing sugar alcohols to be isolated in large quantities at high atom economy.
Domino Hydroalkoxylation-[4+2]-Cycloaddition for Stereoselective Synthesis of 1,4-Heterocycle-Fused Chromenes: Rapid Access to the [6-6-7-6] Tetracyclic Core of Cytorhizhins B–D
Fartade, Dipak J.,Gharpure, Santosh J.,Nanda, Santosh K.,Vishwakarma, Dharmendra S.
supporting information, p. 6892 - 6897 (2020/01/25)
A substrate dependent regio- and stereoselective domino hydroalkoxylation-formal-[4+2] cycloaddition is described for the facile synthesis of linear as well as spirocyclic 1,4-heterocycle-fused chromene ketals. Enantiospecific synthesis of oxazepino chromene derivatives was successfully carried out using chiral pool amino alkynols. The developed hydroalkoxylation cascade offered rapid access to the spirocyclic [6-6-7-6] tetracyclic core of cytorhizhins B–D with correct relative configuration.
Practical Cleavage of Acetals by Using an Odorless Thiol Immobilized on Silica
de Léséleuc, Mylène,Kukor, Andrew,Abbott, Shaun D.,Zacharie, Boulos
, p. 7389 - 7393 (2019/12/03)
A practical, efficient and general method was developed for the deprotection of a variety of aromatic and aliphatic acetals to their corresponding catechol or diol derivatives using thiol immobilized on silica gel. This is an application for the well-known commercial solid-supported thiol (SiliaMetS Thiol). The procedure is mild and amenable to scale-up. It does not require inert atmosphere and clean conversions were observed. This method is applicable to substituted 1,3-benzodioxole and aliphatic acetals with different functionalities. It offers the advantage of a general route with high yield, which can be undertaken at ambient temperature.
Hydrogenolysis of sorbitol into valuable C3-C2 alcohols at low H2 pressure promoted by the heterogeneous Pd/Fe3O4 catalyst
Gumina, Bianca,Mauriello, Francesco,Pietropaolo, Rosario,Galvagno, Signorino,Espro, Claudia
, p. 152 - 160 (2018/02/17)
The hydrogenolysis of sorbitol and various C5-C3 polyols (xylitol; erythritol; 1,2- 1,4- and 2,3-butandiol; 1,2-propandiol; glycerol) have been investigated at low molecular hydrogen pressure (5 bar) by using Pd/Fe3O4, as heterogeneous catalyst and water as the reaction medium. Catalytic experiments show that the carbon chain of polyols is initially shortened through dehydrogenation/decarbonylation and dehydrogenation/retro-aldol mechanisms followed by a series of cascade reactions that include dehydrogenation/decarbonylation and dehydration/hydrogenation processes. At 240 °C, sorbitol is fully converted into lower alcohols with ethanol being the main reaction product in liquid phase.
CYCLIC COMPOUND
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Paragraph 0301, (2018/04/13)
The present invention provides compounds having a Toll-like receptor 4 (TLR4) signaling inhibitory action useful as preventive and therapeutic drugs of autoimmune disease and/or inflammatory disease or diseases such as chemotherapy-induced peripheral neuropathy (CIPN), chemotherapy-induced neuropathic pain (CINP), liver injury, ischemia-reperfusion injury (IRI) and the like. The present invention relates to a compound represented by formula (I) and a salt thereof: (wherein, each symbol is explained in greater detail in the specification).
Xylitol Hydrogenolysis over Ruthenium-Based Catalysts: Effect of Alkaline Promoters and Basic Oxide-Modified Catalysts
Rivière, Maxime,Perret, Noémie,Cabiac, Amandine,Delcroix, Damien,Pinel, Catherine,Besson, Michèle
, p. 2145 - 2159 (2017/06/28)
The aqueous-phase hydrogenolysis of xylitol into glycols over Ru/C was performed in the presence and absence of a wide range of concentrations of Ca(OH)2 to investigate the reaction pathway. Without base, epimerization and cascade decarbonylation were the predominant reactions with high selectivities to C5 and C4 alditols and light alkanes at full conversion. Glycol production was obtained by the addition of Ca(OH)2 to promote the retro-aldol reaction. It competed with reactions without base and became the main reaction for a OH?/ xylitol molar ratio Rmol(OH/xylitol) of 0.13, and high selectivities to glycols (56 %) and glycerol (16 %) were observed. However, lactate was a byproduct at up to 27 % with a high base amount (Rmol(OH/xylitol)=0.68). Bifunctional Ru/metal oxide/C catalysts (metal: Zn, Sn, Mn, Sr, W) were synthesized and were able to cleave the C?C bond into glycols without a base promoter. The 3.1 wt %Ru/MnO(4.5 %)/C catalyst was the most active (220 h?1) with reasonable selectivity to glycols (22 %) and glycerol (10 %) and a low production of lactate (1 %). Nevertheless, metal oxide leaching of the catalyst was observed likely because of the production of traces of lactate.
Effect of tungsten surface density of WO3-ZrO2 on its catalytic performance in hydrogenolysis of cellulose to ethylene glycol
Chai, Jiachun,Zhu, Shanhui,Cen, Youliang,Guo, Jing,Wang, Jianguo,Fan, Weibin
, p. 8567 - 8574 (2017/02/10)
One-pot hydrogenolysis of cellulose to ethylene glycol (EG) was carried out on WO3-based catalysts combined with Ru/C. To probe the active catalytic site for breaking the C-C bond of cellulose, a series of WO3-ZrO2 (WZr) catalysts were synthesized and systematically characterized with XRD, Raman, UV-Vis, H2-TPR, DRIFS and XPS techniques and N2 physisorption experiment. It was found that the WO3 crystallites became more easily reduced to W5+-OH species with increasing crystallite size or tungsten surface density of the WZr catalyst owing to the decrease of their absorption edge energy (AEE) originating from weakening their interaction with ZrO2 support. This, as a result, gave higher EG yield at higher tungsten surface density. The structure-activity relationship of the WZr catalyst reveals that the active catalytic site for cleaving the C2-C3 bond of the glucose molecule is the W5+-OH species.
CYCLIC COMPOUNDS
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Paragraph 0701; 0702; 0703, (2016/11/24)
The present invention provides compounds having a Toll-like receptor 4 (TLR4) signaling inhibitory action useful as preventive and therapeutic drugs of inflammatory disease and/or central nervous system disease or diseases such as chemotherapy-induced peripheral neuropathy (CIPN), chemotherapy-induced neuropathic pain (CINP), liver injury, ischemia-reperfusion injury (IRI) and the like. The present invention relates to a compound represented by formula (I) and a salt thereof: (wherein, each symbol is explained in greater detail in the specification).
A facile synthesis of vicinal cis-diols from olefins catalyzed by in situ generated MnxOy nanoaggregates
Dalmizrak, Di?dem,G?ksu, Haydar,Gültekin, Mehmet Serdar
, p. 20751 - 20755 (2015/03/18)
A novel protocol for the practical and green synthesis of vicinal cis-diols from 10.0 mmol olefins by using 5.0 mmol KMnO4 as oxidant and 30.0 mmol H2O2 as co-oxidant is reported. The presented procedure is easy to carry out and enables the direct transformation of linear and cyclic alkenes to the corresponding vicinal cis-diols. The synthesis of vicinal cis-diols by dihydroxylation of olefins with a KMnO4/H2O2 system was catalyzed by in situ generated MnxOy nanoaggregates. The use of H2O2 as a co-oxidant is the key for the protocol to synthesize vicinal cis-diols in high yields, because it assists the oxidation of MnxOy nanoaggregates, which have an active role in the oxidation reaction medium.
