title: Chlorosilphanol A and silphanepoxol, labdane diterpenes from Silphium perfoliatum.
abstract: Two carterochaetols, chlorosilphanol A and silphanepoxol, isolated from the leaves of Silphium perfoliatum were assigned structures 1 and 3, respectively, from spectral studies and with absolute stereochemistry established by X-ray crystallography of 1. Complete 1H- and 13C-nmr assignments for the parent compounds and their acetates 2 and 4 were made at high-field using 1D and 2D methods, and chlorosilphanol A was chemically converted via its acetate to silphanepoxol. Revision of structure for related carterochaetols in the literature is required, in particular with respect to the stereochemistry at C-12 and that of the side-chain.
authors.affiliation: Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, Ohio State University, Columbus 43210-1291.
authors.forename: M J
authors.initials: MJ
authors.lastname: Pcolinski
authors.forename: R W
authors.initials: RW
authors.lastname: Doskotch
authors.forename: A Y
authors.initials: AY
authors.lastname: Lee
authors.forename: J
authors.initials: J
authors.lastname: Clardy
mesh_terms: D002728:Chlorohydrins / Q000737:chemistry / Q000302:isolation & purification*; D018360:Crystallography, X-Ray; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification*; D004852:Epoxy Compounds / Q000737:chemistry / Q000302:isolation & purification*; D005663:Furans / Q000737:chemistry / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D010946:Plants, Medicinal / Q000737:chemistry*
chemical_list: D002728:Chlorohydrins; D004224:Diterpenes; D004852:Epoxy Compounds; D005663:Furans; C089563:chlorosilphanol A; C089562:silphanepoxol