The Newest Member of the Family of Chloralose : Synthesis of β-Ribochloralose and Some Derivatives

Abstract EN

Treatment of D-ribose with chloral in the presence of acid catalyst gives 1,2-O-(S)-trichloroethylidene-α-D-ribofuranose (1) (β-ribochloralose).

Some derivatives of this product (1) were synthesized to be used as an intermediate in carbohydrate chemistry.

Tricyclic orthoester structure (3, 77%) was obtained from the reaction of 1 with potassium t-butoxide.

This novel orthoester is expected to be useful as a glycosyl donor in the formations of new ribofuranoside units.

3-O-Methyl-ribochloralose (5) was synthesized in 75% yield via the methylation of 1.

5-O-Tosyl-ribochloralose (6, 61%) was prepared with monotosylation reaction of 1.

Treatment of 6 with NaN3 in DMF gives a 5-azido-5-deoxy-ribochloralose (7) in 77% yield.

The azidosugar (7) was reduced to 5-amino-5-deoxy-ribochloralose (8, 72%) with triphenylphosphine according to Staudinger’s reduction procedure.