6605-32-9Relevant academic research and scientific papers
Reductive Oxa Ring Opening of 7-Oxabicycloheptan-2-ones. Synthesis of C-α-Galactosides of Carbapentopyranoses
Cossy, Janine,Ranaivosata, Jean-Luc,Bellosta, Veronique,Ancerewicz, Jacek,Ferritto, Rafael,Vogel, Pierre
, p. 8351 - 8359 (1995)
Photoinduced electron transfer from Et3N to 7-oxabicycloheptan-2-ones can generate the corresponding 3-hydroxycyclohexanone derivatives.The method has been applied to the synthesis of C-α-D-galactopyranosides of carbapentapyranoses.Radical α-D-gaactosidation of (+/-)- (1RS,4RS,5RS,6RS)-6-endo-methoxy-3-methylidene-5-exo-(phenylseleno)-7-oxabicyclohept-2-one ((+/-)/51) followed by seleno-Pummerer rearrangement and reduction with Bu3SnH gave (+)-(1R,2S,3S,4R,6S)-((+)-58) and (+)-(1S,2R,3R,4S,6S)-3-endo-methoxy-5-oxo-6-endo--7-oxabicyclo hept-2-endo-yl acetate ((+)-59), which were separated by column chromatography.Irradiation (254 nm) in the presence of Et3N gave (+)-(1S,2R,3R,6R)- ((+)-60) and (+)-(1R,2S,3S,6S)-2-hydroxy-6-methoxy-4-oxo-3-,(2',3',4',6'-tetra-O-acetyl-α-D-galactopyranosyl)methyl>cyclohexyl acetate (+)-61, respectively.NaBH4 reduction and acetylation provided (+)-(1S,2S,3R,4R,5R)- ((+()-62) and (+)-(1R,2R,3S,4S,5S)-5-methoxy-2-cyclohexa-1,3,4-triyl triaceate ((+)-64).
Stereoselective synthesis of α-linked 2-deoxy glycosides enabled by visible-light-mediated reductive deiodination
Wang, Hao,Tao, Jinyi,Cai, Xinpei,Chen, Wei,Zhao, Yueqi,Xu, Yang,Yao, Wang,Zeng, Jing,Wan, Qian
supporting information, p. 17319 - 17323 (2015/02/19)
2-Deoxy sugars and their derivatives occur abundantly in many pharmaceutically important natural products. However, the construction of specific 2-deoxy-glycosidic bonds remains as a challenge. Herein, we report an efficient way to prepare 2-deoxy-a-glycosides by glycosylation of 2-iodo-glycosyl acetate and subsequent visible-light-mediated tin-free reductive deiodination. We have successfully applied the postglycosylational-deiodination strategy in the synthesis of more than 30 mono-, di-, tri-, tetra- and pentadeoxysaccharides with excellent stereoselectivity and efficiency. This method has also been applied to the synthesis of a 2-deoxy-tetrasac-charide containing four a-linkages.
NaBH3CN and other systems as substitutes of tin and silicon hydrides in the light or heat-initiated reduction of halosugars: A tunable access to either 2-deoxy sugars or 1,5-anhydro-itols
Bruyère, Isabelle,Tóth, Zoltan,Benyahia, Hamida,Xue, Jia Lu,Praly, Jean-Pierre
supporting information, p. 9656 - 9662 (2013/10/22)
UV light-promoted reduction of acetobromoglucose by NaBH3CN in t-BuOH afforded 1,3,4,6-tetra-O-acetyl-2-deoxy-α-d-arabino-hexopyranose in high yield and purity, via a Surzur-Tanner rearrangement, while, with 10 mol % thiophenol added, acetylated 1,5-anhydro-d-glucitol was cleanly obtained. Such tin-free and mild reductions, presumed to proceed via radical pathways, were more efficient with NaBH3CN compared to NaBH4 or NaBD 4, and do not occur with acetochloroglucose. Similar reductions to 1,3,4,6-tetra-O-acetyl-2-deoxy-α-d-arabino-hexopyranose were achieved upon heating to 80 C t-BuOH or CH3CN solutions of NaBH3CN and AIBN, but with a lower selectivity due to competing ionic reactions. With other pyranosyl bromides, reductions by NaBH3CN could be tuned similarly (d-galacto), but some (d-manno, 5-thio-d-xylo) gave mainly or exclusively 1,5-anhydro-itols. Other conditions, or reagents promoting SET process, afforded also reduced products, but with lower rates or selectivities. Primary iodides were reduced readily with NaBH3CN under UV light.
Synthesis of α-D-(13) and α-D-(14)-C-linked Galactosides of D-mannose Derivatives. Conformation of α-C-Galactosides.
Ferritto, Rafael,Vogel, Pierre
, p. 2077 - 2092 (2007/10/02)
Reductive radical α-D-galactosidation of 5-exo-(benzeneselenyl)-6-endo-chloro-3-methylidene-7-oxabicycloheptan-2-one with acetobromo-D-galactose, followed by ketone reduction led to (+)-(1R,2S,3R,4S,5S,6S)-5-exo-(benzeneselenyl)-6-endo-chloro-3-end
