Synthesis of Potential Glucosidase‐Inhibitors: D‐Xylopyranoside‐5‐spiro‐l′‐cyclopropanes

The synthesis of the D‐xylopyranose‐5‐spiro‐1′‐cyclopropane 5 , its methyl α‐D‐glycoside 7 and its benzyl β‐D‐glycoside 13 from D‐glucose is described, and their conformation in solution is discussed. A Königs ‐ Knorr glycosidation of 10 reveals the ionic intermediate of a 1, 1‐(dibromocyclopropyl)carboxonium ion type to be stable against opening of the cyclopropane ring. Very weak inhibition of saccharase was observed for the α‐D‐configurated methyl glycoside 7, whereas the β‐D‐configurated benzyl glycoside 13 did not inhibit emulsin.