rac-Methyl (3aR*,4S*,5R*,7aR*)-5,7a-bis-(acet-yloxy)-3-oxo-2-phenyl-octa-hydro-1H-iso-indole-4-carboxyl-ate

Abstract

The title molecule, C20H23NO7, the product of nucleophilic cleavage of the 3a,6-ep-oxy bridge in 1-oxo-2-phenyl-octa-hydro-3a,6-ep-oxy-iso-indole-7-carboxyl-ate, comprises a cis-fused bicyclic system containing a 2-pyrrolidinone ring in an envelope conformation (with the C atom bearing the carboxyl-ate substituent as the flap) and a cyclo-hexane ring in a chair conformation. The carboxyl-ate substituent occupies the equatorial position, whereas the two acet-yloxy substituents are in axial positions. The N atom has a trigonal-planar geometry, the sum of the bond angles being 359.3 (3)°. The dihedral angle between the mean plane of the four planar atoms of the pyrrolidinone ring and the phenyl ring is 25.98 (6)°. In the crystal, mol-ecules are linked into zigzag chains along the c-axis direction by C-H⋯O hydrogen bonds.

Fig. 1.

Reaction of a nucleophilic cleavage of 3a,6-epoxy bridge in 1-oxo-2-phenyloctahydro-3a,6-epoxyisoindole-7-carboxylate.

Fig. 2.

Molecular structure of the title compound. Displacement ellipsoids are shown at the 50% probability level. H atoms are presented as small spheres of arbitrary radius.

Fig. 3.

A portion of the crystal packing of the title compound demonstrating the H-bonded zigzag chains along the c axis. Dashed lines indicate the intermolecular C—H···O hydrogen bonds.