Utlisation d'ylides du phosphore en chimie des sucres. XIII. Synthèse de dérivés des hydroxyméthyl‐3‐ D ‐glucose et‐ D ‐galactose et de composés voisins
1972; Wiley; Volume: 55; Issue: 8 Linguagem: Inglês
10.1002/hlca.19720550813
ISSN1522-2675
AutoresJ. M. J. TRONCHET, Jean‐Marc Bourgeois,
Tópico(s)Phosphorus compounds and reactions
ResumoAbstract The treatment of the 1, 2:5, 6‐di‐O‐isopropylidene‐α‐ D ‐ ribo ‐ and xylo ‐hexofuranos‐3‐uloses with cyanomethylenetriphenylphosphorane led in each case, and in almost quantitative yields, to a pair of geometrical isomers of C‐cyanomethylenic sugars having respectively the ribo and the xylo configurations. Permanganate oxidation of these branched‐chain unsaturated sugars afforded the corresponding gem ‐hydroxyformyl compounds bearing the formyl group on the more hindered face of the molecule. The formyl group of these sugars is easily derivatized to an oximino or reduced to a hydroxymethyl. The configuration at the new asymmetric carbon has been established by comparison with known compounds or by synthesis of a C(3) epimer by the classical route involving a Grignard reagent.
Referência(s)