- Organocatalytic syn-aldol reactions of hydroxy ketones with (S)-isoserinal: Asymmetric synthesis of 6-deoxy-1,5-iminohexitols and related compounds
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An improved and convenient preparation of protected (S)-isoserinal on a large scale is reported. This key intermediate was reacted through organocatalyzed aldol reaction or Wittig based chain extension and functionalization to give enantiopure 1,5,6-trideoxy-1,5-imino-hexitols such as 10a (L-manno) and 10b (D-gluco). These two compounds are of interest as glycosidase inhibitors. The elaborated organocatalytic process includes diastereoselective syn aldol reaction of (S)-isoserinal hydrate and hydroxyacetone or 1-hydroxy-2-octanone and is promoted by various amino acid-based catalysts. Diastereoselectivities of up to 8:1 were achieved, thus establishing a new, efficient synthetic route to these important carbohydrate mimics. A novel protocol for the preparation of 1,5,6-trideoxy-1,5-imino-L- mannitol and 1,5,6-trideoxy-1,5-imino-D-glucitol is reported. The key steps include organocatalyzed syn-selective direct aldol reaction of hydroxyacetone and CBz-protected isoserinal hydrate, followed by reductive amination/ cyclization. Copyright
- Nicolas, Cyril,Pluta, Roman,Pasternak-Suder, Monika,Martin, Olivier R.,Mlynarski, Jacek
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p. 1296 - 1305
(2013/04/10)
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- Organocatalytic syn-aldol reactions of dioxanones with (S)-isoserinal hydrate: Synthesis of L-deoxymannojirimycin and L-deoxyidonojirimycin
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(Chemical Equation Presented) We report a new protocol for synthesis of L-1-deoxymannojirimycin, L-1-deoxyidonojirimycin, and the N-isopropyl derivative of the latter compound from the readily available precursors (S)-isoserinal hydrate and 2-tert-butyl-2
- Palyam, Nagarjuna,Majewski, Marek
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scheme or table
p. 4390 - 4392
(2009/09/06)
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- Substituted imidazole derivatives
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The present invention relates to new substituted imidazole compounds and pharmaceutically acceptable salts, esters or prodrugs thereof, compositions of the new compounds together with pharmaceutically acceptable carriers, and uses of the new compounds. The compounds of the invention have the following general formula:
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Page/Page column 37
(2008/06/13)
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- The Synthesis of Biphenomycin B
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Biphenomycin B, a highly potent antibiotic against Gram-negative, β-lactam-resistant bacteria, which was previously isolated from culture filtrates of Streptomyces griseorubiginosus No. 43708, has now been synthesized.
- Schmidt, Ulrich,Meyer, Regina,Leitenberger, Volker,Lieberknecht, Albrecht,Griesser, Helmut
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p. 275 - 277
(2007/10/02)
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- Total synthesis of the biphenomycins; II. Synthesis of protected (2S,4R)-4-hydroxyornithines
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Improved synthetic methods for the preparation of three differently protected (2S,4R)-4-hydroxyornithine (10, 16, 24) have been developed which obviously can be used for the construction of the other stereoisomers. Formation of the corresponding α,β-dideh
- Schmidt,Meyer,Leitenberger,Stabler,Lieberknecht
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p. 409 - 413
(2007/10/02)
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