Crystal and molecular structure of 4-amino-4-carboxyl thiapyran

4-Amino-4-carboxylthiapyran crystallizes in space groupP2₁/c witha = 10.61,b = 6.55,c= 10.97 Å, ß =96.3 °, andZ = 4. The structure was solved by the heavy-atom method, with 897 observed reflections, and refined to anR of 0.093. The packing of the structure is found to be very similar to that in the structure of 1-aminocyclohexane carboxylic acid. The conformation of the thiapyran ring exists in the “puckered chair” form.