(8aR,9R)-9-Hy-droxy-7,8,8a,9-tetra-hydro-furo[3,2-f]indolizin-6(4H)-one.

The title compound, C(10)H(11)NO(3), crystallizes with four independent mol-ecules in the asymmetric unit. Their geometries are very similar and corresponding bond distances are almost identical. The central six-membered ring of the indolizine moiety adopts a envelope conformation [the displacement of the flap atom (the C atom opposite the N atom) being 0.539 (2), 0.548 (3), 0.509 (3) and 0.544 (3) Å in the four molecules], while the conformation of the oxopyrrolidine ring is close to that of a flat envelope. The displacements of the non-fused C atom opposite the C=O group of the pyrrolidine ring of the four mol-ecules are 0.366 (3), 0.335 (3), 0.173 (3) and -0.310 (3) Å. In the crystal, O-H⋯O hydrogen bonds link the mol-ecules into chains, which run parallel to the c axis. The absolute configuration was assigned from the synthesis.