title: Total synthesis of natural enantiomers of heliespirones A and C via the diastereoselective intramolecular Hosomi-Sakurai reaction.
abstract: A full account of the development of a novel type of the intramolecular Hosomi-Sakurai reactions of the substrates with a p-benzoquinone and an allylsilane moieties connected by an ether linkage is described. This transformation proceeds via an addition-elimination sequence and provides the products with two stereogenic centers through a 1,3(or 1,4)-asymmetric induction in good to excellent diastereoselectivities. A reasonable mechanistic possibility for the reaction, determination of the stereochemistry for the product, and scope and limitation of the transformation are also discussed. The methodology developed here can successfully be applied to the enantiocontrolled total synthesis of the natural enantiomers of (-)-heliespirone A and (+)-heliespirone C, which have been isolated from sunflower Helianthus annuus L. as allelochemicals.
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokushima, 1-78-1 Sho-machi, Tokushima 770-8505, Japan.
authors.forename: Akari
authors.initials: A
authors.lastname: Miyawaki
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kikuchi
authors.forename: Masu
authors.initials: M
authors.lastname: Niki
authors.forename: Yuki
authors.initials: Y
authors.lastname: Manabe
authors.forename: Makoto
authors.initials: M
authors.lastname: Kanematsu
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Yokoe
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yoshida
authors.forename: Kozo
authors.initials: K
authors.lastname: Shishido
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D016227:Benzoquinones / Q000138:chemical synthesis / Q000737:chemistry*; D002384:Catalysis; D015394:Molecular Structure; D012717:Sesquiterpenes / Q000138:chemical synthesis* / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000475:Alkenes; D016227:Benzoquinones; D012717:Sesquiterpenes; D012821:Silanes; C511847:allylsilane; C552388:heliespirone A; C520941:heliespirone C