Jürgen Schulz

Selektive monotosylierung von 1,6-anhydro-β-D-glucofuranose und darstellung der 1,6:3,5-dianhydro-α-L-idofuranose, des ersten vertreters einer neuen klasse von dianhydrohexosen

Abstract Monotosylation of 1,6-anhydro-β- D -glucofuranose is a highly selective process, which yields the 5- O -tosyl derivative 2 preferentially (77%). By-products of the reaction are the 2- O -monotosyl derivative (6%) and the 2,5- and 3,5-di- O -tosyl derivatives (both 5%). The substitution pattern of all compounds was derived from n.m.r. spectra, especially from those of the acetylated compounds. Attempts to use 2 in the synthesis of 1,6-anhydro-α- L -idofuranose by intermolecular nucleophilic substitution failed, but instead yielded 1,6:3,5-dianhydro-α- L -idofuranose. This first representative of a new class of dianhydrohexoses was characterized by n.m.r. and m.s. Acetylation gave the 2-monoacetate showing an n.m.r. spectrum in agreement with the proposed structure. This tricyclic structure is expected to be very rigid and is composed of four-, five-, six-, seven-, and eight-membered rings.