3,3': 5,6-Di-O-isopropylidene-3-C-hydroxy-methyl-(D)-allono-1,4-lactone: an organic structure containing large unoccupied voids

The Kiliani reaction of D-hamamelose with sodium cyanide, followed by acetonation, affords crystalline 3,3′:5,6-di-O-isopropylidene-3-C- hydroxymethyl-D-allono-1,4-lactone, C13H20O7, a carbon-branched sugar with potential as an enantiomerically pure carbohydrate scaffold. The lactone has one single free hydroxyl group unprotected, with six other functional groups protected in a single step as ketals or esters. The resulting crystal structure is unusual in that it contains large voids (544 Å3) within which there is no evidence of included solvent. © 2007 International Union of Crystallography All rights reserved