- Synthesis of a constrained polyfunctional bicyclic iminocyclitol scaffold from l-sorbose via a tandem sequence including stereoselective intramolecular Huisgen cycloaddition
-
The synthesis of a functionalized (azido, amino, and hydroxy) 8-oxa-3-azabicyclo[3.2.1]octane framework and its conversion into a protected sugar amino acid and a tricyclic framework is described. The sequence includes a one-pot Huisgen 1,3-dipolar cycloaddition, with decomposition to an aziridine and subsequent ring opening by azide. The stereoselectivity observed in the Huisgen cycloaddition reaction is attributed to minimization of allylic strain.
- O'Reilly, Ciaran,O'Brien, Colin,Murphy, Paul V.
-
-
Read Online
- Zaragozic acid: Unusual stereochemical dependence in anhydride formation of carbohydrate templates
-
As a part of study on zaragozic acid bicyclic core, unusual observations in anhydro-ring formation depending on the stereochemistry at C-6 of the carbohydrate templates have been described.
- Gurjar,Das,Sadalapure
-
-
Read Online
- A Green and Sustainable Route to Carbohydrate Vinyl Ethers for Accessing Bioinspired Materials with a Unique Microspherical Morphology
-
Synthesizing chemicals and materials from renewable sources is one of the main aims of modern science. Carbohydrates represent excellent renewable natural raw materials that are ecofriendly, inexpensive, and biologically compatible. A green procedure has been developed for the vinylation of carbohydrates by using readily available calcium carbide. Various carbohydrates were utilized as starting materials, resulting in mono-, di-, and tetravinyl ethers in high to excellent yields (81–92 %). The synthesized biobased vinyl ethers were utilized as monomers in free radical and cationic polymerizations. A unique combination of a smooth surface and intrinsic microcompartments was achieved in the synthesized materials. Two types of biobased materials were prepared involving microspheres and intrinsic hollow compartments in polymers. Scanning electron microscopy with built-in ion beam cutting was applied to reveal the spatial hierarchical structures in 3D space.
- Rodygin, Konstantin S.,Werner, Irina,Ananikov, Valentine P.
-
-
Read Online
- 2,3:4,6-Di-O-isopropyl-idene - L-sorbofuran-ose and 2,3-O-isopropyl-idene - L-sorbofuran-ose
-
In the title compounds, C12H20O6, (I), and C9H16O6, (II), the five-membered furan-ose ring adopts a 4 T 3 conformation and the five-membered 1,3-dioxolane ring adopts an E 3 conformation. The six-membered 1,3-dioxane ring in (I) adopts an almost ideal O C 3 conformation. The hydrogen-bonding patterns for these compounds differ substanti-ally: (I) features just one intra-molecular O - H...O hydrogen bond [O...O = 2.933 (3) A], whereas (II) exhibits, apart from the corresponding intra-molecular O - H...O hydrogen bond [O...O = 2.7638 (13) A], two inter-molecular bonds of this type [O...O = 2.7708 (13) and 2.7730 (12) A]. This study illustrates both the similarity between the con-formations of furan-ose, 1,3-dioxolane and 1,3-di-oxane rings in analogous isopropyl-idene-substituted carbohydrate structures and the only negligible influence of the presence of a 1,3-dioxane ring on the conformations of furan-ose and 1,3-dioxolane rings. In addition, in comparison with reported analogs, replacement of the -CH2OH group at the C1-furan-ose position by another group can considerably affect the conformation of the 1,3-dioxolane ring.
- Langer, Vratislav,Steiner, Bohumil,Koos, Miroslav
-
-
Read Online
- A carbohydrate-based approach for the total synthesis of sawaranospirolide C
-
A diastereoselective carbohydrate-based synthesis of the oxaspirolactone sawaranospirolide C was accomplished by utilizing one-pot cascade of acetonide deprotection/hemiacetal formation/spirolactonization as the key step.
- Yu, Shuai,Liu, Yinxin,Shang, Chengxiang,Du, Yuguo,Liu, Jun
-
supporting information
(2021/04/22)
-
- Composition with a polymer and an oxidation-catalyst
-
The present invention relates to a polymer composition with an increased rate of oxygen-uptake by the presence of an oxidation catalyst. The invention further relates to a process to increase the rate of oxygen-uptake by a polymer composition. The invention also relates to a process to increase the oxo-biodegradability of a polymer composition and to the use of such a composition for the preparation of a product having a controlled lifetime. The invention further relates to a process to increase the rate of oxygen-scavenging in a composition containing a carbon-containing polymer, the composition obtained by this method and its use in the preparation of an oxygen-scavenging product. The present invention further relates to objects containing an oxygen scavenging layer containing such a composition.
- -
-
Page/Page column 17
(2013/04/10)
-
- A carbohydrate-based synthesis of the C13-C22 fragment of amphidinolide X
-
A facile carbohydrate-based route was developed for the synthesis of the tetrahydrofuran (C13-C22) fragment of amphidinolide X. Starting from L-sorbose, the key reactions followed include the stereoselective synthesis of a quaternary center at C1, Barton-
- Gurjar, Mukund K.,Yellol, Gorakh S.,Mohapatra, Debendra K.
-
scheme or table
p. 1753 - 1758
(2012/06/01)
-
- Triphenylphosphine polymer-bound/iodine complex: A suitable reagent for the preparation of O-isopropylidene sugar derivatives
-
O-Isopropylidene derivatives of sugars are readily prepared by using the Lewis acid and dehydrating agent triphenylphosphine polymer-bound/I2 complex. This new method is characterized by smooth, non-equilibrating reaction conditions and a very clean, simple work-up, making it particularly suitable for O-isopropylidenation of sugars under mild conditions and with low environmental impact. Georg Thieme Verlag Stuttgart.
- Pedatella, Silvana,Guaragna, Annalisa,D'Alonzo, Daniele,De Nisco, Mauro,Palumbo, Giovanni
-
p. 305 - 308
(2007/10/03)
-
- Inhibition of the D-fructose transporter protein GLUT5 by fused-ring glyco-1,3-oxazolidin-2-thiones and -oxazolidin-2-ones
-
The glucose transporter 5 (GLUT5) - a specific D-fructose transporter - belongs to a family of facilitating sugar transporters recently enlarged by the human genome sequencing. Prompted by the need to develop specific photolabels of these isoforms, we have studied the interaction of conformationally locked D-fructose and L-sorbose derived 1,3-oxazolidin-2-thiones and 1,3-oxazolidin-2-ones to provide a rational basis for an interaction model. The inhibition properties of the D-fructose transporter GLUT5 by glyco-1,3-oxazolidin-2-thiones and glyco-1,3-oxazolidin-2-ones is now reported. In vitro, the fused-rings systems tested showed an efficient inhibition of GLUT5, thus bringing new insights on the interaction of D-fructose with GLUT5.
- Girniene, Jolanta,Tatibouet, Arnaud,Sackus, Algirdas,Yang, Jing,Holman, Geoffrey D.,Rollin, Patrick
-
p. 711 - 719
(2007/10/03)
-
- Synthesis and evaluation of 1,5,6-trideoxy-6,6-difluoro-1,5-imino-D-glucitol (1,6-dideoxy-6,6-difluoronojirimycin) as a glucosidase inhibitor
-
1,5,6-Trideoxy-6,6-difluoro-1,5-imino-D-glucitol hydrochloride (2) and 1,5,6-trideoxy-6,6-difluoro-1,5-imino-D-glucitol (3) have been synthesized from L-sorbose. The formation of the C-5 difluoromethyl group was accomplished by difluorination of a carbony
- Szarek, Mark A.,Wu, Xinfu,Szarek, Walter A.
-
p. 165 - 170
(2007/10/03)
-
- A new method of acetonation with the zeolite HY as catalyst. Synthesis of O-lsopropylidene sugar derivatives
-
Zeolite HY proved to be a suitable catalyst for the acetonation of sugars. The method consists of a very simple and economic experimental procedure, in which the catalyst is recovered and can be regenerated. Reaction with D-galactose, L-arabinose, D-glucose, D-xylose, L-sorbose, D-glucofuranurono-6,3-lactone, D-ribose and its methyl glycoside led to the formation of di-O- and/or mono-O-isopropylidene derivatives in yields from 37-75%. Reaction with D-galactose and L-arabinose afforded the synthesis of the corresponding furanose derivatives as major products, together with minor quantities of the thermodynamically more stable pyranose derivatives. Acetonation of D-glucose, D-galactose, L-arabinose, D-xylose, L-sorbose, D-ribose, methyl β-D-ribofuranoside and D-glucofuranurono-6,3-lactone was performed by reaction with acetone using the zeolite HY as catalyst. Synthesis of O-isopropylidene derivatives was accomplished in moderate to good yields (37-75%). The method consists of a very simple and economic experimental procedure, in which the catalyst is recovered and can be regenerated. Reaction with D-galactose and L-arabinose afforded the synthesis of the corresponding di-O-isopropylidene and mono-O-isopropylidene furanose derivatives as major products, together with minor quantities of the thermodynamically more stable pyranose derivatives.
- Rauter, Amelia P.,Ramoa-Ribeiro, Fernando,Fernandes, Ana C.,Figueiredo, Jose A.
-
p. 6529 - 6540
(2007/10/02)
-
- Highly Regio- and Stereo-specific Preparation of a New Carbohydrate-based 1,3-Oxazin-2-one by the INIR Method and its Applications in Some Asymmetric Transformations
-
Preliminary experiments show that a new gulonic acid-derived 1,3-oxazin-2-one, prepared by an intramolecular nitrene insertion reaction (INIR) method, serves to control both asymmetric aldol and Diels-Alder reactions with excellent stereo-selection.
- Banks, Malcolm R.,Cadogan, J. I. G.,Gosney, Ian,Gaur, Suneel,Hodgson, Philip K. G.
-
p. 2447 - 2458
(2007/10/02)
-
- Synthesis of Polymerizable Hexose Derivatives
-
Polymerizable esters of methacrylic and acrylic acid with di-O-isopropylidenehexoses as alcohol components have been synthesized.
- Kossmehl, Gerhard,Volkheimer, Juergen
-
p. 1127 - 1130
(2007/10/02)
-
- The Phenylacetyl (PhAc) Group as Enzymatically Removable Protecting Function for Peptides and Carbohydrates: Selective Deprotections with Penicillin Acylase
-
Using the modified carbodiimide procedure or EEDQ as coupling reagent, N-Phenylacetyl (PhAc) amino acids are condensed in good yields with amino acid methyl, benzyl, allyl, and tert-butyl esters to give totally protected dipeptides.The PhAc group is stabl
- Waldmann, Herbert
-
p. 1175 - 1180
(2007/10/02)
-
- GAS CHROMATOGRAPHY-MASS SPECTROMETRY OF HEXULOSES AND PENTULOSES AS THEIR O-ISOPROPYLIDENE DERIVATIVES: ANALYSIS OF PRODUCT MIXTURES FROM TRIOSE ALDOL-CONDENSATIONS
-
Identification and quantitation of hexuloses and pentuloses in mixtures has been achived by gas chromatography-mass spectrometry of their O-isopropylidene derivatives.The method has been applied to product mixtures from triose aldol-condensations.The use of strongly basic anion-exchange resins as catalysts in the aldol condensation gives considerably higher proportions of fructose than when alkali or alkaline-earth hydroxides are applied.
- Morgenlie, Svein
-
p. 215 - 222
(2007/10/02)
-