Indium-Mediated Reaction of 1-Bromo-1-nitroalkanes with Aldehydes: Access to 2-Nitroalkan-1-ols
作者:Raquel G. Soengas、Amalia M. Estévez
DOI:10.1002/ejoc.201000662
日期:2010.9
A novel method for the preparation of 2-nitroalkan-1-ols by an indium-promoted reaction of bromonitromethane with a variety of aldehydes is reported. The reaction was also performed with 2-bromo-2-nitropropanes to afford 2,2-dialkyl-2-nitroalkan-1-ols. The use of chiral sugar-derived aldehydes furnished the corresponding 2-nitroalkan-1-ols with excellent stereoselectivity. The utility of the novel
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.