title: A general entry to antifeedant sesterterpenoids: total synthesis of (+)-norleucosceptroid A, (-)-norleucosceptroid B, and (-)-leucosceptroid K.
abstract: The first asymmetric total synthesis of the antifeedant terpenoids (+)-norleucosceptroid A, (-)-norleucosceptroid B, and (-)-leucosceptroid K has been accomplished. This highly concise synthetic route was guided by our efforts to develop a platform for the collective synthesis of a whole family of antifeedant natural products. The synthesis features a Hauser-Kraus-type annulation followed by an unprecedented, highly efficient intramolecular dilactol aldol-type condensation reaction to produce the 5,6,5 skeleton. The developed synthetic route proceeds for norleucosceptroid A and B in 16 steps (longest linear sequence) from known compounds.
authors.affiliation: Department of Chemistry and Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstrasse 5-13, 81377 Munich (Germany).
authors.forename: Cedric L
authors.initials: CL
authors.lastname: Hugelshofer
authors.forename: Thomas
authors.initials: T
authors.lastname: Magauer
mesh_terms: D001688:Biological Products / Q000138:chemical synthesis* / Q000737:chemistry; D054830:Sesterterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D001688:Biological Products; D054830:Sesterterpenes; C000598931:leucosceptroid K; C579659:norleucosceptroid A; C579660:norleucosceptroid B
keywords: Claisen reaction; leucosceptroids; natural products; terpenoids; total synthesis