title: Synthesis of phytuberin. 4-endo-tet acid-catalyzed cyclization of alpha-hydroxy epoxides.
abstract: The total synthesis of phytuberin, a phytoalexin of the Solanum genus, from (-)-alpha-santonin is reported. The key steps include (a) reductive cleavage of the C-O bond of the gamma-lactone with concomitant protection of the C1 double bond, (b) Sharpless stereocontrolled hydroxy-assisted epoxidation of allylic alcohol 6 and simultaneous deprotection of the C1 double bond, (c) a rare 4-endo-tet acid-catalyzed cyclization of an alpha-hydroxy epoxide, and (d) an unprecedented 4-exo selenocyclization of a homoallylic alcohol.
authors.affiliation: Instituto de Productos Naturales y Agrobiología del C.S.I.C., Carretera de La Esperanza 3, 38206 La Laguna, Tenerife, Spain.
authors.forename: Thierry
authors.initials: T
authors.lastname: Prangé
authors.forename: María S
authors.initials: MS
authors.lastname: Rodríguez
authors.forename: Ernesto
authors.initials: E
authors.lastname: Suárez
mesh_terms: D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D003500:Cyclization; D004852:Epoxy Compounds / Q000737:chemistry*; D007202:Indicators and Reagents; D015394:Molecular Structure; D010946:Plants, Medicinal / Q000737:chemistry; D012500:Santonin / Q000737:chemistry; D012717:Sesquiterpenes / Q000138:chemical synthesis*; D032322:Solanum / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D004852:Epoxy Compounds; D007202:Indicators and Reagents; D012717:Sesquiterpenes; D012500:Santonin; C008908:phytuberin