- Synthesis of chiral hydroxyl phospholanes from D-mannitol and their use in asymmetric catalytic reactions
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Chiral hydroxyl monophosphane 3 [(2S,3S,4S,5S)-3,4-dihydroxy-2,5-dimethyl-1-phenylphospholane] and bisphospholanes 5a [1,2-bis[(2S,3S,4S,5S)-3,4-dihydroxy-2,5-dimethylphospholanyl]benzene] and 5b [1,2-bis[(2S,3S,4S,5S)-2,5-diethyl-3,4-dihydroxyphospholanyl]benzene] were synthesized from readily available D-mannitol in high yields. Strategies for protection and deprotection of OH-groups in the presence of phosphines have been explored. Rate acceleration in the Baylis - Hillman reaction was observed when a hydroxyl phosphine was used as the catalyst. Rhodium complexes with chiral bisphospholanes are highly enantioselective catalysts for the asymmetric hydrogenation of various kinds of functionalized olefins such as dehydroamino acid derivatives, itaconic acid derivatives, and enamides. An interesting feature of the hydroxyl phospholane system is that hydrogenation of some substrates can be carried out in water with >99% ee and 100% conversion (e.g., itaconic acid).
- Li, Wenge,Zhang, Zhaoguo,Xiao, Dengming,Zhang, Xumu
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p. 3489 - 3496
(2007/10/03)
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- A practical approach to the synthesis of dianhydro sugars
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Chiral tetrols derived from various carbohydrate precursors have been converted into the corresponding dianhydro sugar derivatives in a one pot procedure. The course of reaction very much depends upon the protecting groups used. In case of D-mannitol and
- Lohray, Braj B.,Chatterjee, Manashi,Jayamma, Yaruva
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p. 1711 - 1724
(2007/10/03)
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- Synthesis of azasugars as potent inhibitors of glycosidases
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A series of enantiomerically pure azasugars (2,5-dideoxy-2,5-imino-D-mannitol, 1-deoxynojirimycin, 1-deoxymannojirimycin, and related compounds) was synthesized from D-mannitol via aminoheterocyclization of C2-symmetric bis-epoxides and subsequently followed by ring isomerization in few cases. These compounds have been evaluated as inhibitors of several glycosidases (α- and β-D-glucosidases, α-D-mannosidase and α-L-fucosidase). Inhibition studies indicate notably that the polyhydroxylated azepanes are inhibitors of glycosidases, with K(i) in the micromolar range.
- Le Merrer, Yves,Poitout, Lydie,Depezay, Jean-Claude,Dosbaa, Isabelle,Geoffroy, Sabine,Foglietti, Marie-Jose
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p. 519 - 533
(2007/10/03)
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- Polyhydroxylated Piperidines and Azepanes from D-Mannitol. Synthesis of 1-Deoxynojirimycin and Analogues
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D-mannitol and L-iditol bis-epoxides, easily obtained from D-mannitol, are convenient substrates for the synthesis of polyhydroxylated piperidines and azepanes, via a nucleophilic opening of one epoxy function followed by a spontaneous intramolecular ring closure.Using this strategy 1-deoxynojirimycin and analogues were prepared. - Key words: D-mannitol, Piperidine, Azepane, 1-deoxynojirimycin, 1,5-dideoxy-1,5-imino-L-gulitol, β-Glycosidase inhibitor.
- Poitout, Lydie,Merrer, Yves Le,Depezay, Jean-Claude
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p. 3293 - 3296
(2007/10/02)
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