- NMR spectroscopy and conformational analysis of 3-deoxy-3-C-(hydroxymethyl)-1,2:5,6-di-O-isopropylidene-α-D-allofuran ose
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Homonuclear and heteronuclear 1- and 2-dimensional NMR techniques have been used to establish stereochemical and conformational relationships in the hydroxymethyl furanoside 2. Concurrent with the NMR studies, theoretical calculations were performed on this compound using computer-assisted model building (MacroModel) and molecular mechanics (MM2). From the NOE and J-coupling constraints obtained from NMR experiments, refined structures for this compound in two different solvents have been identified and optimized. The 'solvent effects' observed in the NMR spectra for 2 are interpreted in terms of the differences in the requirements for intramolecular electrostatic stabilization in the two solvents. Homonuclear and heteronuclear 1- and 2- dimensional NMR techniques have been used to establish stereochemical and conformational relationships in the hydroxymethyl furanoside 2. Concurrent with the NMR studies, theoretical calculations were performed on this compound using computer-assisted model building (MacroModel) and molecular mechanics (MM2). From the NOE and J-coupling constraints obtained from NMR experiments, refined structures for this compound in two different solvents have been identified and optimized. The ″solvent effects″ observed in the NMR spectra for 2 are interpreted in terms of the differences in the requirements for intramolecular electrostatic stabilization of the two solvents.
- Lankin,Nugent,Rao
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- Rearrangements of haloalkynol derivatives of glucofuranose
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(matrix presented) Bromoalkynol derivatives of diacetone glucose undergo rearrangements to dihaloenol ethers contained in furo[3,4-b]furan cores when treated with halonium-producing reagents.
- Blandino, Maureen,McNelis, Edward
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- LARGE SCALE PROCESS FOR PREPARING 1,2,4, 6-TETRA-0-ACETYL-3-AZID0-3-DE0XY-D-GALACT0PYRAN0SIDE
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The present invention relates to a process for preparing a compound of formula (X), wherein said process is suitable for large scale synthesis.
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Page/Page column 9; 10
(2021/10/11)
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- A practical access to glucose- and allose-based (5+5) 3- spiropseudonucleosides from a common intermediate
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A practical access to glucose-based and allose-based spirooxazolidinones is reported. The synthetic sequence consisting of TEMPO-catalyzed oxidation of 1,2:5,6-di-O-isopropylidene-α-d-glucofuranose, Henry reaction, and reduction provides amino alcohol with allo-configuration on a multigram scale. Alternatively, water elimination from Henry products followed by a rehydration gives an access to diastereomerically pure glucose-based nitro alcohol which upon reduction provides complementary amino alcohol with gluco-configuration. The latter amino alcohols are transformed into spirooxazolidinones (3-spiropseudonucleosides) via their N-Cbz or N-phenylcarbamate derivatives. The title compounds easily undergo N-derivatization and give highly crystalline materials. Two of the newly obtained (5+5) 3-spiropseudonucleosides are characterized by X-ray crystallography.
- Turks, Maris,Rodins, Vitalijs,Rolava, Evija,Ostrovskis, Pavels,Belyakov, Sergey
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supporting information
p. 5 - 15
(2013/07/27)
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- First and efficient synthesis of phosphonodifluoromethylene analogues of nucleoside 3′-phosphates: Crucial role played by sulfur in construction of the target molecules
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Phosphoric esters of secondary alcohols are ubiquitous in biological systems. However, despite the obvious interest of the corresponding difluoromethylene phosphonates as isopolar mimics, a single example of such an analogue featuring this particular subs
- Lopin, Chrystel,Gautier, Arnaud,Gouhier, Geraldine,Piettre, Serge R.
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p. 14668 - 14675
(2007/10/03)
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- α-Chloronitroso compounds derived from carbohydrate ketones: Cycloadditions with cyclic dienes, a synthesis of (-)-physoperuvine and a formal synthesis of (+)-epibatidine
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1,2-O-Isopropylidene-α-D-xylofuranose 9 was converted into 5-O-(tert-butyldiphenylsilyl)-3-chloro-3-deoxy-1,2-O-isopropylidene-3-C-nitroso- α-o-xylofuranose 17 in four steps, and a similar α-chloronitroso compound 8 was synthesised from 1,2:5,6-di-O-isopropylidene-α-o-glucofuranose 6, the structures of 8 and 17 being confirmed by X-ray crystallography. Reaction of 8 or 17 with cyclohexa-1,3-diene in the presence of small amounts of water gave the cycloadduct (1S,4R)-3-aza-2-oxabicyclo[2.2.2]oct-5-ene, as its hydrochloride (-)-2, in ≥96% ee. Reactions of either 8 or 17 with cyclohepta-1,3-diene similarly gave (1R,5S)-7-aza-6-oxabicyclo[3.2.2]non-8-ene hydrochloride (-)-25 with ≥96% ee, but reactions with cyclopentadiene proceeded differently, with 17 giving the nitrone (E)-(3 R,5 R)-3-[5′-O-(tert-butyldiphenylsilyl)-3′-deoxy-1′,2′-O-is opropylidene-α-D-erythro-pentofuranos-3′-ylidene-amino]-5-chlorocycl opentene N-oxide 19, the structure of which was determined by X-ray crystallography. The dihydrooxazines (-)-25 and (-)-2 were used in syntheses of (-)-physoperuvine (-)-34 and (+)-epibatidine (+)-40, respectively. A pseudoenantiomeric α-chloronitroso compound 51 was also prepared from 2,3-O-isopropylidene-α-L-sorbofuranose 44, and reaction of 51 with cyclohexa-1,3-diene gave (+)-2 with 97% ee.
- Hall, Adrian,Bailey, Patrick D.,Rees, David C.,Rosair, Georgina M.,Wightman, Richard H.
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p. 329 - 343
(2007/10/03)
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- Synthetic studies on zoapatanol: Construction of oxepanes via an intramolecular 1,3-dipolar cycloaddition strategy
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The nitrones derived from β-allyloxyaldehydes with a β-quaternary centre cyclized to give six- instead of seven-membered O-heterocycles exclusively whereas a nitrile oxide derived from a γ-allyloxyaldehyde with a γ-quaternary centre cyclized to yield an o
- Shing, Tony K.M.,Wong, Ching-Hung,Yip, Ting
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p. 1323 - 1340
(2007/10/03)
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- A New Approach to 6-Deoxy-D-allofuranose- and 6-Deoxy-L-talofuranose Derivatives from 1,2:5,6-Di-O-isopropylidene α-D-Glucofuranose
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3-O-Acetyl-1,2-O-isopropylidene-α-D-allofuranose (2b) was prepared from 1,2:5,6-di-O-isopropylidene-α-D-allofuranose (1b).Treatment of 2b with triphenylphosphine-diethyl azodicarboxylate afforded regio- and stereospecifically the 5,6-epoxy-α-D-allo deriva
- Zsoldos-Mady, Virag,Zbiral, Erich
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p. 1325 - 1338
(2007/10/02)
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