Structure of leuconolam sesquihydrate.

8a-Ethyl-7,8,8a,10,11,12a-hexahydro-12a- hydroxyindolizino[8,1-ef][1]benzazonine-6,13-(5H,9H)-dione sesquihydrate, C19H22N2O3.3/2H2O, Mr = 353.42, triclinic, P1, a = 9.250 (2), b = 13.366 (3), c = 9.217 (2) A, alpha = 97.786 (3), beta = 119.590 (3), gamma = 70.726 (3) degrees, V = 934.8 A3, Z = 2, Dx = 1.255 g cm-3, Mo K alpha,lambda = 0.71073 A, mu = 0.839 cm-1, F(000) = 378, T = 293 K. The final R value is 0.061 for 1646 significant [I greater than 3 sigma(I)] reflections. The alkaloid from the leaves of Rhazia stricta is built up by a benzene ring ortho disubstituted with a 4,5-dihydro-5-hydroxy-2-oxo-pyrrol-1,4,5-triyl unit and an N(CO)R- unit forming a twelve-membered ring.