Crystal structure of methyl (3RS,4SR,4aRS,11aRS,11bSR)-5-oxo-3,4,4a,5,7,8,9,10,11,11a-deca­hydro-3,11b-ep­oxy­azepino[2,1-a]iso­indole-4-carboxyl­ate

The title compound, C(15)H(19)NO(4), is the a product of the esterification of the corresponding carbonic acid with methanol. The mol­ecule comprises a fused tetra­cyclic system containing three five-membered rings (2-pyrrolidinone, tetra­hydro­furan and di­hydro­furan) and one seven-membered ring (azepane). The five-membered rings have the usual envelope conformations, with the quaternary C atom being the flap atom for the 2-pyrrolidinone ring, and the ether O atom being the common flap atom for the remaining rings. The seven-membered azepane ring adopts a chair conformation with the methine and middle methyl­ene C atoms lying above and below the mean plane defined by the remaining five atoms. The carboxyl­ate substituent is rotated by 77.56 (5)° with respect to the base plane of the tetra­hydro­furan ring. In the crystal, the mol­ecules are bound by weak C—H⋯O hydrogen-bonding inter­actions into puckered layers parallel to (001).