title: Scalable Total Syntheses of (-)-Hapalindole U and (+)-Ambiguine H.
abstract: TheStigonemataceaefamily of cyanobacteria produces a class of biogenetically related indole natural products that include hapalindoles and ambiguines. In this full account, a practical route to the tetracyclic hapalindole family is presented by way of an eight-step, enantiospecific, protecting-group-free total synthesis of (-)-hapalindole U that features an oxidative indole-enolate coupling. With gram-scale access to hapalindole U, the first total synthesis of an ambiguine alkaloid, (+)-ambiguine H, was completed via an isonitrile-assisted prenylation of an indole followed by a photofragmentation cascade.
authors.affiliation: Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Maimone
authors.affiliation: Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Ishihara
authors.affiliation: Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
authors.forename: Phil S
authors.initials: PS
authors.lastname: Baran
keywords: Alkaloid; Indole; Protecting-group-free; Terpene; Total synthesis