title: (3R,5S)-5(3)-Carb-oxy-3,4,5,6-tetra-hydro-2H-1,4-thia-zin-4-ium-3(5)-carboxyl-ate.
abstract: The molecule of the zwitterionic title compound, C(6)H(9)NO(4)S, which lies on a mirror plane, shows a puckered chair conformation of the six-membered ring with the S and N atoms out of the mean plane of the other four C atoms by 0.929 (2) and 0.647 (2) Å, respectively. The ionized carboxyl group is equatorially oriented. The hydrogen-bonding network includes very short O-H⋯O [2.470 (2) Å] and N-H⋯S [3.471 (2) and 3.416 (2) Å] inter-molecular contacts.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Portalone
authors.forename: Alberto
authors.initials: A
authors.lastname: Cassetta
authors.forename: Marcello
authors.initials: M
authors.lastname: Colapietro
authors.forename: Susanne Heidi
authors.initials: SH
authors.lastname: Plattner