Ergotaminine.

The title compound {systematic name: (6aR,9S)-N-[(2R,5S,10aS,10bS)-5-benzyl-10b-hy-droxy-2-methyl-3,6-dioxoocta-hydro-8H-oxazolo[3,2-a]pyrrolo-[2,1-c]pyrazin-2-yl]-7-methyl-4,6,6a,7,8,9-hexa-hydro-indolo[4,3-fg]quinoline-9-carboxamide}, C(33)H(35)N(5)O(5), was formed by an epimerization reaction of ergotamine. The non-aromatic ring (ring C of the ergoline skeleton) directly fused to the aromatic rings is nearly planar [maximum deviation = 0.317†(4)†à ] and shows an envelope conformation, whereas ring D, involved in an intra-molecular N-H⋯N hydrogen bond exhibits a slightly distorted chair conformation. The structure displays chains running approximately parallel to the diagonal of bc plane that are formed through N-H⋯O hydrogen bonds.