- An efficient, one-pot synthesis of fosfomycin dialkyl esters from (R)-2-tosyloxypropanal
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(R)-2-Tosyloxypropanal (4) was prepared from D-mannitol in a 7-step sequence (51% overall yield). Addition of dialkyl phosphonates to 4 in the presence of titanium isopropoxide and the subsequent treatment with DBU stereoselectively afforded, in one-pot, fosfomycin dimethyl (5a) and dibenzyl (5b) esters both in 58% isolated yield.
- Hanaya, Tadashi,Nakamura, Yuichi,Yamamoto, Hiroshi
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p. 983 - 989
(2008/09/19)
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- Synthesis and DNA-binding ability of pyrrolo[2,1-c][1,4]benzodiazepine- azepane conjugates
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A series of pyrrolobenzodiazepine-azepane conjugates linked through different alkane spacers have been prepared and their DNA thermal denaturation studies have been carried out. One of the compound (4b), elevates the DNA helix melting temperature of the CT-DNA by 2.0°C after incubation for 36 h at 37°C.
- Kamal, Ahmed,Reddy, D. Rajasekhar,Reddy, P. S. Murali Mohan,Rajendar
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p. 1160 - 1163
(2007/10/03)
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- Asymmetric catalysis based on chiral phospholanes and hydroxyl phospholanes
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Chiral phosphine ligands derived from chiral natural products including D-mannitol and tartaric acid. The ligands contain one or more 5-membered phospholane rings with multiple chiral centers, and provide high stereoselectivity in asymmetric reactions.
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Page column 15
(2010/02/06)
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- Asymmetric catalysis based on chiral phospholanes and hydroxyl phospholanes
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Chiral phosphine ligands derived from chiral natural products including D-mannitol and tartaric acid. The ligands contain one or more 5-membered phospholane rings with multiple chiral centers, and provide high stereoselectivity in asymmetric reactions.
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Page column 15
(2010/01/30)
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- Highly Flexible Synthetic Routes to Functionalized Phospholanes from Carbohydrates
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Highly functionalized phospholanes 15, 17, and 26 and the corresponding diastereomers in which the configurations of the phospholane carbon-2 and carbon-5 are inverted can be readily prepared from D-mannitol by displacement of the appropriate dimesylate or cyclic sulfate with dilithium-phosphide reagents. The diols from which these ligands are prepared can also be converted into diarylphosphinite ligands. A route to related monophosphines bearing hemilabile tert-butylthio groups is also described. Complexes of these ligands and of related deprotected derivatives are potentially useful for enantioselective catalysis in organic and aqueous media.
- Yan, Yuan-Yong,RajanBabu
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p. 900 - 906
(2007/10/03)
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- Synthesis of C2-symmetric guanidino-sugars as potent inhibitors of glycosidases
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A series of enantiomerically pure C2-Symmetric guanidino-sugars was synthesized from D-mannitol. The first method described involves direct opening of a bis-epoxide by guanidine, whereas the second one deals with a mercury-catalyzed transformation of a cyclic thiourea into a N,N',N'- trisubstituted guanidine as a key step. The biological activity of these compounds towards several glycosidases has been evaluated. One of them (5) was found to selectively inhibit α-L-fucosidase of bovin kidney (2.8 μM). (C) 2000 Elsevier Science Ltd.
- Le Merrer, Yves,Gauzy, Laurence,Gravier-Pelletier, Christine,Depezay, Jean-Claude
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p. 307 - 320
(2007/10/03)
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- 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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- Rhodium-hydroxyl bisphospholane catalyzed highly enantioselective hydrogenation of dehydroamino acids and esters
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A chiral hydroxyl bisphospholane, 1,2-bis[(2S,3S,4S,5S)-3,4-dihydroxyl-2,5-dimethylphospholanyl]benzene (4), was synthesized from readily available D-mannitol. Its Rh(I) complex catalyzes asymmetric hydrogenation of dehydroamino acids and their ester derivatives with excellent enantioselectivities (98 to >99% ee).
- Li, Wenge,Zhang, Zhaoguo,Xiao, Dengming,Zhang, Xumu
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p. 6701 - 6704
(2007/10/03)
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- A convergent synthesis of optically active aspyrone
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Aspyrone (1) was elaborated in an optically pure form by the key reaction involving a nucleophilic addition of δ-lactone enolate to 2-tosyloxyaldehyde and a subsequent in situ formation of epoxide.
- Sugiyama,Murayama,Yamashita
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p. 7343 - 7344
(2007/10/02)
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- SYNTHESIS OF DIEPOXIDES AND DIAZIRIDINES, PRECURSORS OF ENANTIOMERICALLY PURE α-HYDROXY AND α-AMINO ALDEHYDES OR ACIDS, FROM D-MANNITOL
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Specific activations or protections of the hydroxyl groups of 3-4-O-isopropylidene-D-mannitol 2 followed by intramolecular SN2 reactions, lead to the chiral diepoxides 4 and 7 and to the chiral diaziridines 9 and 13 precursors of enantiomerically pure α-hydroxy and α-amino aldehydes or acids.
- Merrer, Yves Le,Dureault, Annie,Greck, Christine,Micas-Languin, Dominique,Gravier, Christine,Depezay, Jean-Claude
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p. 541 - 548
(2007/10/02)
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