NOVEL REACTIONS OF CARBOHYDRATE DITHIANES - 1,4-DITHIEPINS VIA A 1,4-ALKOXY RELAY

When heated, 1,3-dithiane derivatives of common sugars which bear a me sylate at the 5-position (and are otherwise O-methylated) form 1,4-dit hiepins by a novel mechanism in which ring expansion is coordinated wi th intramolecular relay of the 2-alkoxy group to the 5 position. Addit ion of a nucleophile such as azide to the reaction produces novel stru ctures resulting from the trapping of intermediates along the pathway.