A Selective C-C Bond Cleavage of D-GIucose and D-Galactose by the Titanium(IV) Chloride-catalyzed Photoreaction

Abstract

The titanium(N) chloride-catalyzed photoreaction has been carried on some sugar molecules. Under these reaction conditions, D-glucose [9] and D-galactose [12} underwent a selective bond cleavage at the C5-C6 position, producing the corresponding pentodialdose derivatives [10a] and [13], respectively. The reaction is considered to proceed through 1) isomerization to furanoside structure [15}, 2) formation of a titanium chelate at the C5 and C6 hydroxyl groups [17], and 3) electron transfer within the chelate. The good selectivity of the reaction was rationalized by assuming the highest reactivity at the 1,2-diol system including the primary hydroxyl group. © 1984, The Chemical Society of Japan. All rights reserved.