Synthesis of enantiopure 2-C-glycosyl-3-nitrochromenes.

Raquel G Soengas, Humberto Rodríguez-Solla, Artur M S Silva, Ricardo Llavona, Filipe A Almeida Paz

文献索引：J. Org. Chem. 78(24) , 12831-6, (2013)

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摘要

A novel methodology has been developed to obtain enantiopure 2-C-glycosyl-3-nitrochromenes. First, (Z)-1-bromo-1-nitroalkenes were prepared from the corresponding sugar aldehydes through a sodium iodide-catalyzed Henry reaction with bromonitromethane followed by elimination of the resulting 1-bromo-1-nitroalkan-2-ols. In the next step, reaction of the sugar-derived (Z)-1-bromo-1-nitroalkenes with o-hydroxybenzaldehydes afforded enantiopure (2S,3S,4S)-3-bromo-3,4-dihydro-4-hydroxy-3-nitro-2H-1-benzopyrans, which, upon SmI2-promoted β-elimination, yielded chiral enantiopure 2-C-glycosyl-3-nitrochromenes.