title: An efficient one-pot synthesis of 5, 9-cyclo-1, 11-oxido-pregn-16-ene-3, 20-dione from 9-bromide-11-hydroxypregna-1, 4, 16-trien-3, 20-dione by two annulation reactions.
abstract: An efficient method to prepare 5, 9-cyclo-1, 11-oxido-pregn-16-ene-3, 20-dione in one pot was reported. Treatment of 9-bromide-11-hydroxypregna-1, 4, 16-trien-3, 20-dione with Raney Ni in absolute ethanol afforded 5, 9-cyclo-1, 11-oxido-pregn-16-ene-3, 20-dione by two annulation reactions in reasonable yield. The absolute configuration was also confirmed by X-ray crystal analysis.
authors.affiliation: Department of Medicinal Chemistry, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, PR China.
authors.forename: Ping
authors.initials: P
authors.lastname: Jia
authors.forename: Xuling
authors.initials: X
authors.lastname: Wu
authors.forename: Yongping
authors.initials: Y
authors.lastname: Yu
authors.forename: Guolin
authors.initials: G
authors.lastname: Zhang
mesh_terms: D018360:Crystallography, X-Ray; D054879:Halogenation; D011281:Pregnatrienes / Q000737:chemistry*; D011282:Pregnenediones / Q000737:chemistry*; D011283:Pregnenes / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D013379:Substrate Specificity
chemical_list: C539866:5, 9-cyclo-1, 11-oxido-pregn-16-ene-3, 20-dione; C539867:9-bromide-11-hydroxypregna-1, 4, 16-trien-3, 20-dione; D011281:Pregnatrienes; D011282:Pregnenediones; D011283:Pregnenes