Total Synthesis of Salimabromide: A Tetracyclic Polyketide from a Marine Myxobacterium.

J Am Chem Soc

Institute of Organic Chemistry and Center for Molecular Biosciences , University of Innsbruck, Innrain 80-82 , 6020 Innsbruck , Austria.

Published: July 2018

Salimabromide is an antibiotic polyketide that was previously isolated from the obligate marine myxobacterium Enhygromyxa salina, and its densely functionalized and conformationally rigid tetracyclic framework is unprecedented in nature. Herein we report the first chemical synthesis of the target structure by employing a series of well-orchestrated, robust transformations, highlighted by an acid-promoted, powerful Wagner-Meerwein rearrangement/Friedel-Crafts cyclization sequence to forge the two adjacent quaternary carbon centers embedded in the tetrahydronaphthalene. A high-yielding ketiminium mediated [2+2]-cycloaddition was also utilized for the simultaneous construction of the remaining three stereocenters.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6061937PMC
http://dx.doi.org/10.1021/jacs.8b06228DOI Listing

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