The Rearrangement Reaction of Some Acetylated Unsaturated 2-Acetamidoaldose Derivatives. Selective Removal of one N-Acetyl Group from 2-(N-acetylacetamido) Compounds
Two pairs of anomers, the l ,4,6-tri-0-acetyl-2-(N-acetylacetamido)-
2,3-dideoxy-o-hex-2-enopyranoses of the erythro- (II and III)
and the threo- series (IV and VI) have been prepared and character;
ized. The molecular conformation of these substances has been
discussed on the basis of their NMR spectral characteristics. It is
suggested that the a-anomers II and IV adopt the H~ conformation
as the favorable one, while the B-anomers III and VI most probably
tend to take a slightly modified H~ conformation.
A convenient preparative method for selective removal of one
N-acetyl group from 0-acetylated N-acetylacetamido compounds is
described. The reaction can be carried out in aqueous dioxane solution
at room temperature in the presence of an ammonium salt
at pH ca. 9
