13039-94-6Relevant academic research and scientific papers
Fluorinated Ketene Dithioacetals. 3. A Radical Entry to α-Perfluoroalkyl Ketene Dithioacetals. Application to Sugar Derivatives.
Bergeron, S.,Brigaud, T.,Foulard, G.,Plantier-Royon, R.,Portella, C.
, p. 1985 - 1988 (1994)
α-Perfluoroalkyl ketene dithioacetals were synthesized by radical perfluoroalkylation of ketene dithioacetals with perfluoroalkyl iodide and sodium dithionite in a basic medium.Application to sugar derived ketene dithioacetals gave results depending strongly on the sugar structure. - Key-words: ketene dithioacetals, radical perfluoroalkylation, perfluoroalkylated sugars.
Convergent and stereoselective synthesis of (-)-zeaenol
Kumar, Rayala Naveen,Meshram
, p. 5669 - 5677 (2015/08/03)
Stereoselective synthesis of (-)-zeaenol has been accomplished from d-xylose as a chiral pool starting material. The key steps of this convergent synthetic strategy involves a Stille coupling, a Noyori reduction, a Julia-Kocienski olefination and a macrolactonization to obtain (-)-zeaenol. We have also explored a Sonogashira coupling along with a Trost protocol for the intramolecular hydrosilylation on the homopropargylic alcohol system as an alternative synthetic approach to this molecule.
SUGAR-LINKER-DRUG CONJUGATES
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Paragraph 0202, (2014/09/29)
The present disclosure relates to sugar-linker-drug conjugates, of the formula [A-B-]n-L-D, wherein A is a saccharide; B is a spacer, n is an integer selected from 1 to 3; L is a linker group and D is a drug having a chemically reactive functional group selected from the group consisting of a primary or secondary amine, hydroxyl, sulfhydryl, carboxyl, aldehyde and ketone. Pharmaceutical compositions comprising the conjugates and methods of using thern are also provided.
Synthesis of α-l-rhamnosyl ceramide and evaluation of its binding with anti-rhamnose antibodies
Long, David E.,Karmakar, Partha,Wall, Katherine A.,Sucheck, Steven J.
, p. 5279 - 5289 (2014/12/11)
An α-l-rhamnosyl ceramide (1, α-l-RhaCer) has been prepared that was recognized by anti-l-rhamnose (anti-Rha) antibodies. During these studies we explored the use of an α-l-rhamnosyl thioglycoside and a trichloroacetimidate as a glycosyl donors. Subsequently, the acceptors desired for glycosylation, 3-O-benzoylazidosphingosine or 3-O-alloxycarbonylsphingosine, were prepared from d-xylose. The thioglycoside donor, 2,3,4-tri-O-acetyl-1-(4-tolyl)thio-α-l-rhamnopyranoside, and the trichloroacetimidate donor, 2,3,4-tri-O-acetyl-1-(2,2,2-trichloroethanimidate)-α-l-rhamnopyranoside, were synthesized in 50% and 78% yield overall, respectively. The synthesis of the glycosylation acceptor employed an addition-fragmentation olefination that was successfully carried out in 53% yield. With the successful synthesis of key intermediates, α-l-RhaCer (1) was prepared without any insurmountable obstacles. Anti-Rha antibodies were prepared in BALB/c mice by immunizing them with rhamnose-ovalbumin (Rha-Ova) with Sigma Adjuvant System (SAS) and the anti-l-Rha antibodies were isolated from the blood sera. Liposomes and EL4 tumor cells were used as model systems to demonstrate the ability of 1 to insert into a lipid bilayer. The interaction of the liposomes or the EL4 cells with α-l-RhaCer (1) and anti-Rha antibodies were investigated by fluorescence microscopy and flow cytometry, respectively, to confirm the ability of glycolipid 1 to be displayed on the tumor cell surface as well as the ability to be recognized by anti-Rha antibodies.
trans-acetonide controlled endo-selective intramolecular nitrone-alkene cycloaddition of hept-6-enoses: A facile entry to calystegines, tropanes, and hydroxylated aminocycloheptanes
Shing, Tony K. M.,Wong, Wai F.,Ikeno, Taketo,Yamada, Tohru
, p. 207 - 209 (2007/10/03)
(Chemical Equation Presented) High-yielding endo-selective intramolecular nitrone-alkene cycloaddition (INAC) reactions of hept-6-enoses controlled by a trans-acetonide to give bridged bicyclo[4.2.1]isoxazolidines exclusively are realized for the first ti
Use of the composite material RuO2/BaTi4O9 as an environmentally benign solid catalyst for the oxidative cleavage of olefins
Okumoto, Hiroshi,Ohtsuka, Kazuhiro,Banjoya, Shinji
, p. 3201 - 3205 (2008/09/20)
Catalytic use of a composite material, RuO2/BaTi 4O9, in combination with NaIO4 in EtOAc-H 2O has been shown to efficiently cleave alkenes, affording ketones, aldehydes and/or carboxylic acids in high yields. Georg Thieme Verlag Stuttgart.
Studies on enolization of aldehydo-aldose derivatives
Eitelman, Stephen J.,Horton, Derek
, p. 2658 - 2668 (2007/10/03)
Acetylation of the 2,3-O-isopropylidene derivative (1) of d-glyceraldehyde with hot acetic anhydride in the presence of sodium acetate give a mixture of (Z)- and (E)-enol acetates (2 and 3), together with the acetylated racemic aldehydrol (4) of 1. Likewise, the acyclic aldehydo 2,3:4,5-diisopropylidene acetals of d- and l-arabinose, d-xylose, and d-ribose underwent conversion into enol acetates, with the (Z) isomers preponderating, and convertible photochemically into the corresponding (E) isomers. Under other conditions of acetylation, the aldehydo derivatives were converted into the corresponding aldehydrol diacetates.
A short and practical route to 3-O-benzoyl azidosphingosine
Ohlsson, Joergen,Magnusson, Goeran
, p. 91 - 94 (2007/10/03)
A short and practical route to 3-O-benzoyl azidosphingosine from D-xylose is described. The synthesis avoids the use of expensive and hazardous chemicals (i.e. mercury salts), and it is reproducible up to at least a 20 g scale. Furthermore, the synthesis proceeds to 3-O-benzoyl azidosphingosine with a minimum of protection group manipulation, by exploiting a regioselective protection of the primary HO-1 with thexyldimethylsilyl chloride.
Design, synthesis, and transfection biology of novel cationic glycolipids for use in liposomal gene delivery
Banerjee,Mahidhar,Chaudhuri,Gopal,Rao
, p. 4176 - 4185 (2007/10/03)
The molecular structure of the cationic lipids used in gene transfection strongly influences their transfection efficiency. High transfection efficiencies of non-glycerol-based simple monocationic transfection lipids with hydroxyethyl headgroups recently reported by us (Banerjee et al. J. Med. Chem. 1999, 42, 4292-4299) are consistent with the earlier observations that the presence of hydroxyl functionalities in the headgroup region of a cationic lipid contributes favorably in liposomal gene delivery. Using simple sugar molecules as the source of multiple hydroxyl functionalities in the headgroup region of the transfection lipids, we have synthesized four novel simple monocationic transfection lipids, namely, 1-deoxy-1-[dihexadecyl(methyl)-ammonio]-D-xylitol (1), 1-deoxy-1-[methyl(ditetradecyl)ammonio]-D-arabinitol (2), 1-deoxy-1-[dihexadecyl(methyl)ammonio]-D-arabinitol (3) and 1-deoxy-1-[methyl(dioctadecyl)ammonio]-D-arabinitol (4), containing hydrophobic aliphatic tails and the hydrophilic arabinosyl or xylose sugar groups linked directly to the positively charged nitrogen atom. Syntheses, chemical characterizations, and the transfection biology of these novel transfection lipids 1-4 are described in this paper. Lipid 1, the xylosyl derivative, showed maximum transfection on COS-1 cells. All the lipids showed transfection with cholesterol as colipid and not with dioleoylphosphatidylethanolamine (DOPE). Radioactive quantitation of free and complexed DNA combined with ethidium bromide exclusion measurements suggest that though nearly 70% of the DNA exists as complexed DNA, the DNA may not have condensed as was observed with other cationic lipids. Presence of additional (more than two) hydroxyl functionalities in the headgroup of the cationic lipids appears to have improved the transfection efficiency and made these lipids less cytotoxic compared to two-hydroxyl derivatives.
Syntheses of the D-aldopentoses from non-carbohydrate sources
Banwell, Martin G.,De Savi, Chris,Hockless, David C. R.,Pallich, Susanne,Watson, Keith G.
, p. 885 - 888 (2007/10/03)
The cis-1,2-dihydrocatechols 5-7, which are obtained in high yield and ca. 99.8% ee by microbial oxidation of the corresponding aromatic compound, have been converted, via reaction sequences involving three distinct types of one-carbon deletion processes, into the four D-aldopentoses.
