Ethyl 3,4-bis-(acet-yloxy)-2-(4-meth-oxy-phen-yl)pyrrol-idine-1-carboxyl-ate

The title pyrrolidine compound, C₁₈H₂₃NO₇, is a tetra-substituted species in which the five-membered ring has a twisted conformation with the twist occurring in the C-C bond bearing the adjacent acet-yloxy substituents; the C_m-C_a-C_a-C_p torsion angle is -40.76 (18)° [m = methyl-ene, a = acet-yloxy and p = phen-yl]. The N atom, which is sp ²-hybridized [sum of bond angles = 359.4°], bears an ethyl-carboxyl-ate substitutent and is connected to a methyl-ene-C atom on one side and a carbon atom bearing a 4-meth-oxy-phenyl group on the other side. Minor disorder is noted in the ethyl-carboxyl-ate substituent as well as in one of the acet-yloxy groups; the major components of the disorder have site occupancies of 0.729 (9) and 0.62 (3), respectively. The most notable feature of the mol-ecular packing is the formation of helical, supra-molecular chains aligned along the b-axis direction whereby the carbonyl-O atom not involved in a disordered residue accepts C-H⋯O inter-actions from methyl-ene-H and two-C atom separated methine-H atoms to form a six-membered {⋯HCCCH⋯O} synthon.