A novel general route to higher aldoses is proposed involving transformation of the starting monosaccharides-2,3-dehydro-2-3-dideoxyaldonic acid or to its ester, by Knoevenage-Doebner condensation or Wittig reaction, folowed by double bond hydroxylation to give higher aldonic acids. The acids are reduced to the corresponding aldoses by conventional methods.
New asymmetric syntheses of (-)-methyl shikimate 1 and (-)-5a-carba-beta-D-gulopyranose 11 from D-arabinose through a common route which employed Mukaiyama-type intramolecular aldolization as a key step were described. (C) 2009 Elsevier Ltd. All rights reserved.