Regioselective intramolecular ring closure of 2-amino-6-bromo-2,6-dideoxyhexono-1,4-lactones to 5- or 6-membered iminuronic acid analogues: synthesis of 1-deoxymannojirimycin and 2,5-dideoxy-2,5-imino-D-glucitol

Org Biomol Chem. 2008 May 21;6(10):1779-86. doi: 10.1039/b719631h. Epub 2008 Mar 28.

Abstract

1-Deoxymannojirimycin (8c) was synthesised from 2-amino-6-bromo-2,6-dideoxy-D-mannono-1,4-lactone (7) by intramolecular direct displacement of the C-6 bromine employing non-aqueous base treatment followed by reduction of the intermediate methyl ester. Likewise, using aqueous base at pH 12, ring closure took place by 5-exo attack on the 5,6-epoxide leading to 2,5-dideoxy-2,5-imino-L-gulonic acid (9b), which was reduced to 2,5-dideoxy-2,5-imino-D-glucitol (9b). The method was further applied to 2-amino-6-bromo-2,6-dideoxy-D-galacto- as well as D-talo-1,4-lactones (14 and 15). However, only the corresponding six-membered ring 1,5-iminuronic acid mimetics, namely (2R,3R,4S,5R)-3,4,5-trihydroxypipecolic acid (2,6-dideoxy-2,6-imino-D-galactonic acid, 16) and (2S,3R,4S,5R)-3,4,5-trihydroxypipecolic acid (2,6-dideoxy-2,6-imino-D-talonic acid, 17), were obtained. The corresponding enantiomers, L-galacto- as well as L-talo-2-amino-6-bromo-2,6-dideoxy-1,4-lactones ent-14 and ent-15, reacted accordingly to give the D-galacto- and L-altro-1,5-iminuronic acid mimetics, (2S,3S,4R,5S)-3,4,5-trihydroxypipecolic acid (2,6-dideoxy-2,6-imino-L-galactonic acid, ent-16) and (2R,3S,4R,5S)-3,4,5-trihydroxypipecolic acids (2,6-dideoxy-2,6-imino-L-talonic acid, ent-17), respectively.

MeSH terms

  • 1-Deoxynojirimycin / chemical synthesis*
  • 1-Deoxynojirimycin / chemistry
  • Acids / chemistry*
  • Amines / chemistry*
  • Bromine Compounds / chemistry*
  • Cyclization
  • Lactones / chemistry*
  • Molecular Structure
  • Oxygen / chemistry
  • Sorbitol / analogs & derivatives*
  • Sorbitol / chemical synthesis
  • Sorbitol / chemistry
  • Stereoisomerism
  • Uronic Acids / chemistry*

Substances

  • 2,5-dideoxy-2,5-imino-D-glucitol
  • Acids
  • Amines
  • Bromine Compounds
  • Lactones
  • Uronic Acids
  • iminuronic acid
  • 1-Deoxynojirimycin
  • Sorbitol
  • Oxygen