Methyl (9aR*,10S*,11R*,13aS*,13bS*)-9-oxo-6, 7,9,9a,10,11-hexahydro-5H,13bH-11,13a-epoxypyrrolo-[2′,1′:3,4][1,4] diazepino[2,1-a]isoindole-10-carboxylate

The title compound, C17H18N2O4, is the methyl ester of the adduct of intra-molecular Diels-Alder reaction between maleic anhydride and 1-(2-fur-yl)-2,3,4,5-tetra-hydro-1H-pyrrolo-[1,2-a] [1,4]diazepine. The molecule comprises a fused penta-cyclic system containing four five-membered rings (viz. pyrrole, 2-pyrrolidinone, tetra-hydro-furan and dihydro-furan) and one seven-membered ring (1,4-diazepane). The pyrrole ring is approximately planar (r.m.s. deviation = 0.003 Å) while the 2-pyrrolidinone, tetrahydrofuran and dihydro-furan five-membered rings have the usual envelope conformations. The central seven-membered diazepane ring adopts a boat conformation. In the crystal, molecules are bound by weak intermolecular C - H⋯O hydrogen-bonding interactions into zigzag chains propagating in [010]. In the crystal packing, the chains are stacked along the a axis. © Toze et al. 2011.