Crystal and molecular structure of endo,endo-2,6-bis(phenylcarbamoyloxy)-cis-bicyclo[3.3.0]octane

Abstract

The crystal and molecular structure of the title compound (II) has been determined by a three-dimensional X-ray analysis. Crystals are orthorhombic, space group F2dd, with a= 5·289(7), b= 12·948(9), and c= 55·15(4)Å, Z= 8, molecular symmetry 2. The structure was solved by a combination of Patterson and Fourier techniques and refined by full-matrix least-squares methods with anisotropic thermal parameters to R 0·033 for 583 reflections measured by diffractometer. Discrete molecules are linked in the c direction by N–H ⋯ O hydrogen bonds [3·084(7)Å]. The oxygen substituents on the cis-bicyclo[3.3.0]octane nucleus are endo, and the system itself is skewed to relieve intramolecular O ⋯ H interactions which would otherwise be severe; as a consequence there is a marked puckering of the unique five-membered ring which adopts a half-chair conformation with approximately C₂ symmetry. Bond lengths have expected values.