One-pot synthesis of vicinal aminoalkanols from sugar aldehydes
作者:Raquel G. Soengas、Artur M.S. Silva
DOI:10.1016/j.tet.2013.02.072
日期:2013.4
A novel synthetic method of carbohydrate derived vicinal aminoalcohols, from sugaraldehydes and bromonitroalkanes, has been developed. It involves an indium-catalyzed one-pot Henry reaction and nitro group reduction, and proceeds with a remarkably high anti-selectivity. The reaction of the intermediate aminoalcohols with alkylating agents furnished the corresponding carbohydrate-based tertiary aminoalcohols
We present herein an improved synthesis of nitro sugars, consisting of a Henry-type reaction of bromonitromethane and sugar aldehydes. The reaction can be promoted by either SmI2 or indium metal, yielding in both cases high yields and good diastereoisomeric ratios. However, while the SmI2-promoted reaction is very sensitive to steric factors and only gives satisfactory results with bromonitromethane, the indium-mediated reaction is not subjected to this limitation, giving excellent results with bromonitromethane as well as more hindered bromonitroalkanes.