title: Syntheses and absolute stereochemistries of UPA0043 and UPA0044, cytotoxic antibiotics having a p-quinone-methide structure.
abstract: The first syntheses of new antibiotics UPA0043 and UPA0044 were accomplished starting from commercially available 18beta-glycyrrhetinic acid and vanillin. The present syntheses involve the coupling of a sesquiterpenoid aldehyde and an aryllithium, the stereoselective formation of a p-quinone-methide system, and regioselective intramolecular cyclization via an epoxy ring opening. [reaction: see text]
authors.affiliation: Department of Applied Chemistry, Keio University, Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
authors.forename: K I
authors.initials: KI
authors.lastname: Takao
authors.forename: T
authors.initials: T
authors.lastname: Sasaki
authors.forename: T
authors.initials: T
authors.lastname: Kozaki
authors.forename: Y
authors.initials: Y
authors.lastname: Yanagisawa
authors.forename: K I
authors.initials: KI
authors.lastname: Tadano
authors.forename: A
authors.initials: A
authors.lastname: Kawashima
authors.forename: H
authors.initials: H
authors.lastname: Shinonaga
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000138:chemical synthesis* / Q000737:chemistry* / Q000494:pharmacology; D045563:Indolequinones; D007211:Indoles / Q000737:chemistry*; D015394:Molecular Structure; D011809:Quinones / Q000138:chemical synthesis* / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000903:Antibiotics, Antineoplastic; D045563:Indolequinones; D007211:Indoles; D011809:Quinones; C445721:UPA0043; C445720:UPA0044; C068040:quinone methide