Structural and synthetic studies on maleic anhydride and related diacid natural products. Issue 1 (3rd January 2020)

• Record Type: Journal Article
• Authors: Heard, David M.; Tayler, Emyr R.; Cox, Russell J.; Simpson, Thomas J.; Willis, Christine L.
• Is Part Of: Tetrahedron. Volume 76:Issue 1(2019)
• Publication Date: 2020-01-03
• Subjects: Nonadride -- Natural product synthesis -- Fungal natural products -- Structure elucidation -- Tricladic acid; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tet.2019.130717
• Languages: English
• ISSNs: 0040-4020

Abstract

Abstract: A concise approach has been developed for the total syntheses of tricladic acids A, B and C previously isolated from Tricladium castaneicola confirming the structures of these fungal natural products. The required ( E )-1, 3-diene scaffolds were generated with complete stereocontrol via coupling of the appropriate nitronate with an unsaturated bromo-diester which was prepared in 2 steps from citraconic anhydride. The reported structures of the anhydride waquafranone B and the parent diacid were synthesised leading to revision of the originally proposed structure of the natural product and, in accord with Sutherland, confirming that cyclic anhydrides with exo -dienes are unstable. Biomimetic dimerisations of the proposed monomers of the nonadride scytalidin were investigated. Graphical abstract: Image 1 Highlights: Tricladic acids A, B and C were prepared confirming the structures of these fungal natural products. The structure of the fungal natural product waquafranone B was determined. A monomer proposed to be involved in scytalidin biosynthesis was prepared.