title: Efficient syntheses of oncinotine and neooncinotine.
abstract: We have synthesized two natural alkaloids, oncinotine (1) and neooncinotine (2), by means of efficient ring-closing metathesis (RCM) reactions. The required dienes for RCM were assembled from three basic components: 2-allylpiperidine (5), 9-decenoic acid (6), and diamines 7. We developed two different methods to achieve the linkage: the Michael addition of acrylamide and two amidations of succinic anhydride. The Grubbs catalyst was used to form the 17- and 18-membered lactams in 50% and 68% yields, respectively.
authors.affiliation: Department of Chemistry, National Central University, Jung-Li City, Taoyuan, Taiwan 320, ROC.
authors.forename: Duen-Ren
authors.initials: DR
authors.lastname: Hou
authors.forename: Hsiu-Yi
authors.initials: HY
authors.lastname: Cheng
authors.forename: Eng-Chi
authors.initials: EC
authors.lastname: Wang
mesh_terms: D000470:Alkaloids / Q000138:chemical synthesis*; D029062:Apocynaceae / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D007769:Lactams / Q000032:analysis / Q000138:chemical synthesis*; D015394:Molecular Structure; D010946:Plants, Medicinal / Q000737:chemistry
chemical_list: D000470:Alkaloids; D007769:Lactams; C014141:oncinotine; C014120:neooncinotine