Crystal structure of (E)-13-(pyrimidin-5-yl)parthenolide

• Main Authors: Shobanbabu Bommagani, Narsimha R. Penthala, Sean Parkin, Peter A. Crooks
• Format: Article
• Language: English
• Published: International Union of Crystallography 2015-12-01
• Series: Acta Crystallographica Section E: Crystallographic Communications
• Subjects: crystal structure; parthenolide; pyrimidine; Heck product
• Online Access: http://scripts.iucr.org/cgi-bin/paper?S2056989015021507

The title compound, C19H22N2O3, {systematic name (1aR,4E,7aS,8E,10aS,10bR)-1a,5-dimethyl-8-[(pyrimidin-5-yl)methylidene]-2,3,6,7,7a,8,10a,10b-octahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-9(1aH)-one} was obtained from the reaction of parthenolide [systematic name (1aR,7aS,10aS,10bR,E)-1a,5-dimethyl-8-methylene-2,3,6,7,7a,8,10a,10b-octahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-9(1aH)-one] with 5-bromopyrimidine under Heck reaction conditions, and was identified as an E isomer. The molecule possesses ten-, five- (lactone) and three-membered (epoxide) rings with a pyrimidine group as a substituent. The ten-membered ring displays an approximate chair–chair conformation, while the lactone ring shows a flattened envelope-type conformation. The dihedral angle between the pyrimidine moiety and the lactone ring system is 29.43 (7)°.