Crystal structure of benzyl 3-oxo-2-oxa-5-aza­bicyclo­[2.2.1]heptane-5-carboxyl­ate

The title compound, C(13)H(13)NO(4) (also known as N-benzyl­oxycarbonyl-4-hy­droxy-l-proline lactone), crystallizes with two mol­ecules in the asymmetric unit. They have slightly different conformations: the fused ring systems almost overlap, but different C—O—C—C torsion angles for the central chains of −155.5 (2) and −178.6 (2)° lead to different twists for the terminal benzene ring. In the crystal, the mol­ecules are linked by C—H⋯O inter­actions, generating a three-dimensional network. The absolute structure was established based on an unchanging chiral centre in the synthesis.