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 ...
