Résumé
Reaction of several α- and β-galactopyranosides with 2,2-dimethoxypropane produced up to five types of mono-, bis-, and tris(isopropylidene)acetals, among which the 3,4-0-iso-propylidene-6-0-(2-methoxyisopropyl) derivatives can be obtained in high yield and be useful intermediates for selective syntheses of 2-, 6-, and 2,6-0-substituted galactose derivatives.
Five types of acetals are obtained from galactopyranosides with Me2(OMe)2. Compounds of type 2 can be prepared in high yield and used for the synthesis of 2-, 6-, or 2,6-0-substituted galactose derivatives.