title: N-(2-Carb-oxy-eth-yl)-2,5-dide-oxy-2,5-imino-d-mannonic acid [(3R,4R,5R)-1-(2-carb-oxy-eth-yl)-3,4-dihy-droxy-5-hy-droxy-methyl-l-proline].
abstract: The absolute stereochemistry of the title compound, C(9)H(15)NO(7), was determined from the use of d-glucuronolactone as the starting material. The compound crystallizes as the zwitterion. The five-membered ring adopts an envelope conformation with the -CH(2)OH-substituted C atom forming the flap. An intramolecular N-H⋯O hydrogen-bond occurs. In the crystal, the compound exists as a three-dimensional O-H⋯O intermolecular hydrogen-bonded network with each mol-ecule acting as a donor and acceptor for four hydrogen bonds.
authors.affiliation: Department of Chemical Crystallography, Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA,  England.
authors.forename: David S
authors.initials: DS
authors.lastname: Edgeley
authors.forename: R Fernando
authors.initials: RF
authors.lastname: Martínez
authors.forename: Sarah F
authors.initials: SF
authors.lastname: Jenkinson
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Nash
authors.forename: George W J
authors.initials: GW
authors.lastname: Fleet
authors.forename: Amber L
authors.initials: AL
authors.lastname: Thompson