The crystal structure of δ-lactone, C9H14O 5, formed in high diastereoselectivity by the Kiliani reaction of a protected 1-deoxyketose was described. It was observed that the δ-lactone compound adopts a boat conformation in which an OH group occupies a flagpole position. The hydroxy group at atom C1 was clearly found to be in a very hindered position, being additionally attached to a tertiary C atom. As usually expected for sugar derivatives, hydrogen bonding was found to occur between molecules.
