Benzylation of aldonolactones with benzyl trichloroacetimidate

A number of aldono-1,4-lactones have been converted to their perbenzylated derivatives by treatment with benzyl trichloroacetimidate. 2,3,6-Trideoxy-d-erythro-hexono-1,4-lactone could be benzylated in dichloromethane, but lactones containing two or more hydroxy-groups were insoluble and could therefore not be benzylated in this solvent. It has now been found that the benzylation can be performed in dioxane and, using this solvent, a number of perbenzylated lactones, including tetra-O-benzyl-d-galactono-1,4-lactone, were prepared in good yields.