Studies on the transformation of nitrosugars into branched chain iminosugars. Part II: Synthesis of (3R,4R,5R,6S)-2,2-bis(hydroxymethyl)azepane-3,4,5,6-tetraol
摘要:
The first stereocontrolled synthesis of (3R,4R,5R,6S)-2,2-bis-(hydroxymethyi)azepane-3,4,5,6-tetraol is described herein. The method involves a novel double Henry reaction of the 3,5-di-O-benzyl-6-deoxy-1,2 -O-isopropyIidene-6-nitro-alpha-D-glucofuranose with formaldehyde followed by a reductive ring closure to give the first branched 1,6-dideoxy-1,6-heptitol described. (C) 2008 Elsevier Ltd. All rights reserved.
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