Scalable total syntheses of (−)-hapalindole U and (+)-ambiguine H. Issue 22 (3rd June 2015)

• Record Type: Journal Article
• Authors: Maimone, Thomas J.; Ishihara, Yoshihiro; Baran, Phil S.
• Is Part Of: Tetrahedron. Volume 71:Issue 22(2015)
• Page Start: 3652
• Page End: 3665
• Publication Date: 2015-06-03
• Subjects: Total synthesis -- Alkaloid -- Terpene -- Indole -- Protecting-group-free; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tet.2014.11.010
• Languages: English
• ISSNs: 0040-4020

Abstract

Abstract: The Stigonemataceae family 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. Graphical abstract: