90633-94-6Relevant articles and documents
Synthesis of glyco-fused bicyclic compounds; Conformationally constrained scaffolds and useful polyfunctional building blocks
Cardona, Francisco,D'Orazio, Giuseppe,Silva, Artur M. S.,Nicotra, Francesco,La Ferla, Barbara
, p. 2549 - 2556 (2014/05/06)
We synthesized fused bicyclic polyfunctional compounds containing a highly hydroxylated pyran ring starting from commercially available methyl glucopyranoside and adopting a RCM annulation approach. The versatile α,β-unsaturated ketone group was introduced on the newly formed ring and, as an example of the potential of these polyfunctionalized building blocks, a tetracyclic compound was synthesized through a Diels-Alder cycloaddition reaction. Bicyclic polyfunctional glycol-fused compounds have been synthesized from commercially available methyl gluco-pyranoside. These molecules, with their high chirality content, presence of an α,β-unsaturated ketone and multiple hydroxyl groups represent useful building blocks for the preparation of complex, optically pure compounds. Copyright
P-Methoxybenzyl-N-phenyl-2,2,2-trifluoroacetimidate: A versatile reagent for mild acid catalyzed etherification
Barroca-Aubry, Nadine,Benchekroun, Mohamed,Gomes, Filipe,Bonnaffé, David
, p. 5118 - 5121 (2013/09/02)
PMB-NPTFA 1a is a new month bench stable and powerful reagent for the formation of PMB ethers. Several alcohols were protected in high yields and short reaction times, using low reagent loading and small catalytic amounts of Bi(OTf)3. The mild
Disaccharide-containing macrocycles by click chemistry and intramolecular glycosylation
Tiwari, Vinod K.,Kumar, Amit,Schmidt, Richard R.
supporting information; experimental part, p. 2945 - 2956 (2012/07/27)
In this study o- and m-xylylene moieties in combination with a triazolylmethyl moiety have been successfully employed as a relatively rigid spacer system in intramolecular glycosylation reactions. Phenyl 3,4,6-tri-O-benzyl-2-O-propargyl-1-thio-D-glucopyra
Temperature-controlled regioselectivity in the reductive cleavage of p-methoxybenzylidene acetals
Hernandez-Torres, Jesus M.,Achkar, Jihane,Wei, Alexander
, p. 7206 - 7211 (2007/10/03)
The regioselective ring opening of pyranosidic 4,6-p-methoxybenzylidene acetals with BH3/Bu2BOTf in THF can be tuned by adjusting the reaction temperature and reagent concentrations. Reductive cleavage at 0 °C resulted in the exclusive formation of 4-O-p-methoxybenzyl (PMB) ethers, whereas reaction at -78 °C produced 6-O-PMB ethers in high yields. The latter condition was observed to be compatible with a variety of acid-sensitive functional groups, including allyl and enol ethers. The presence of water does not interfere with reductive ring opening and may contribute toward in situ generation of H+ as a catalyst for 6-O-PMB ether formation. Reductive cleavage under rigorously aprotic conditions is greatly decelerated, and yields only the 4-O-PMB ether. The temperature-dependent reductive cleavage of the 4,6-acetal can be described in terms of kinetic versus thermodynamic control: Lewis-acid coordination of the more accessible O-6 is favored at higher temperatures, whereas protonation of the more basic but sterically encumbered O-4 predominates at low temperatures.
Substrate dependent intramolecular Pauson-Khand reaction of carbohydrate exo-methylene derivatives. Unexpected formation of fused '[4.1.0] bicycloheptene - pyranose' tricyclic product
Borodkin,Shpiro,Azov,Kochetkov
, p. 1489 - 1492 (2007/10/03)
Attempted Pauson-Khand cyclisation of exo- methylene carbohydrate enynic substrates is described. 3-Exo methylene derivative cyclises to give a normal Pauson-Khand product while cyclisation of a 4-exo methylene analog follows a previously unreported pathway to give fused '[4.1.0] bicycloheptene - pyranose' tricyclic product.
Acetal-bond Cleavage of 4,6-Alkylidenehexopyranosides by Diisobutylaluminium Hydride and by Lithium Triethylborohydride-TiCl4
Mikami, Tetsuhiro,Asano, Hiroyuki,Mitsunobu, Oyo
, p. 2033 - 2036 (2007/10/02)
Regioselective acetal-bond cleavage of 4,6-benzylidene- and 4,6-O-(4-methoxybenzylidene)-α-D-altropyranosides by DIBAL or Li(C2H5)3BH-TiCl4 is described.The sense of regioselectivity could be controlled by suitable choice of the protecying group of hydrox
Regioselective Reductive Ring Opening of 4-Methoxybenzylidene Acetals of Hexopyranosides. Access to a Novel Protective Group Strategy
Johansson, Rolf,Samuelsson, Bertil
, p. 201 - 202 (2007/10/02)
Reduction of fully protected 4,6-O-(4-methoxybenzylidene)hexopyranosides with sodium cyanoborohydride-trifluoroacetic acid in N,N-dimethylformamide, or with trimethylsilyl chloride in acetonitrile, gives the 6- and 4-O-(4-methoxybenzyl) ethers, respectively, in good yields and with good regioselectivity; the 4-methoxybenzyl ether linkage in products containing benzyl ethers or other protective groups is selectively cleaved upon treatment with cerium(IV) ammonium nitrate in aqueous acetonitrile.
Regioselective Reductive Ring-opening of 4-Methoxybenzylidene Acetals of Hexopyranosides. Access to a Novel Protecting-group Strategy. Part 1
Johansson, Rolf,Samuelsson, Bertil
, p. 2371 - 2374 (2007/10/02)
Reduction of fully protected 4,6-O-(4-methoxybenzylidene) hexopyranosides with sodium cyanoborohydride-trifluoroacetic acid in NN-dimethylformamide, or trimethylsilyl chloride in acetonitrile, gives the 6- and 4-O-(4-methoxybenzyl) ethers, respectively, in good yield and good regioselectivity.The 4-methoxybenzyl ether linkage in products containing benzyl ethers or other protective groups is selectively cleaved upon treatment with cerium(IV) ammonium nitrate in aqueous acetonitrile.
