Base catalysed isomerisation of aldoses of the arabino and lyxo series in the presence of aluminate.
Base-catalysed isomerisation of aldoses of the arabino and lyxo series in aluminate solution has been investigated. L-Arabinose and D-galactose give L-erythro-2-pentulose (L-ribulose) and D-lyxo-2-hexulose (D-tagatose), respectively, in good yields, whereas lower reactivity is observed for 6-deoxy-D-galactose (D-fucose). From D-lyxose, D-mannose and 6-deoxy-L-mannose (L-rhamnose) are obtained mixtures of ketoses and C-2 epimeric aldoses. Small amounts of the 3-epimers of the ketoses were also formed. 6-Deoxy-L-arabino-2-hexulose (6-deoxy-L-fructose) and 6-deoxy-L-glucose (L-quinovose) were formed in low yields from 6-deoxy-L-mannose and isolated as their O-isopropylidene derivatives. Explanations of the differences in reactivity and course of the reaction have been suggested on the basis of steric effects.
Ekeberg
Dag
D
Department of Chemistry and Biotechnology, Section Chemistry, Agricultural University of Norway, PO Box 5040, N-1432 As, Norway.
Morgenlie
Svein
S
Stenstrøm
Yngve
Y
D000537:Aluminum Oxide / Q000737:chemistry*; D002236:Carbohydrate Conformation; D002384:Catalysis; D005947:Glucose / Q000031:analogs & derivatives; D006863:Hydrogen-Ion Concentration; D007536:Isomerism; D015394:Molecular Structure; D009005:Monosaccharides / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry; D014994:Xylose / Q000031:analogs & derivatives
D009005:Monosaccharides; D012996:Solutions; D014994:Xylose; D005947:Glucose; D000537:Aluminum Oxide