A New Secondary Metabolite from Alternaria Alternata: Structure Elucidation and Total Synthesis of Altenuic Acid IV. Issue 8 (15th February 2019)

• Record Type: Journal Article
• Authors: Kohler, Dominik; Podlech, Joachim
• Is Part Of: European journal of organic chemistry. Issue 8(2019)
• Page Start: 1748
• Page End: 1753
• Publication Date: 2019-02-15
• Subjects: Mycotoxins -- Fungal metabolites -- Cross‐coupling -- Total synthesis -- Natural products; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.201801801
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract : A putative intermediate in the biosynthesis of altenuic acids I–III was isolated from Alternaria alternata in the 1950ies and a sample survived over the decades. This resorcylic lactone named altenuic acid IV is a composite of a resorcylic and a muconic acid. Its structure was confirmed by NMR spectroscopy and by total synthesis. Altenuic acid IV was here obtained starting with 2‐bromo‐4, 6‐dimethoxybenzene and 4‐methylbenzene‐1, 2‐diol with a total yield of 20 %. The synthesis was achieved in ten steps where the longest sequence consists of seven steps. Key steps were an oxidative ring opening of a bromocresol furnishing a bromomuconate and its Suzuki coupling with a resorcylate‐derived boronate. Abstract : A missing link in the putative biosynthesis of the altenuic acids I–III has been identified and its structure was confirmed by total synthesis. It could be produced in the fungus Alternaria alternata by oxidative ring opening of altenusin.