potassium 9-O-(1,2:5,6-di-O-isopropylidene-α-D-glucofuranosyl)-9-boratabicyclolt;3.3.1gt;nonane in tetrahydrofuran T=-78°C; 48 h; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

sodium tetrahydroborate in tetrahydrofuran 1 h; in air;