title: Ergotaminine.
abstract: 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) Å] 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.
authors.affiliation: Reference Materials, Department of Analytical Chemistry, BAM Federal Institute for Materials Research and Testing, Richard-Willstätter-Strasse 11, D-12489 Berlin-Adlershof,  Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Merkel
authors.forename: Robert
authors.initials: R
authors.lastname: Köppen
authors.forename: Matthias
authors.initials: M
authors.lastname: Koch
authors.forename: Franziska
authors.initials: F
authors.lastname: Emmerling
authors.forename: Irene
authors.initials: I
authors.lastname: Nehls