Synthesis of (–)-Viridin and (–)-Viridiol
Total Synthesis of Viridin and Viridiol.
J. Am. Chem. Soc. 2019;
21 January 2020 (online)
Key words(–)-viridin - (–)-viridol - furanosteroid - [3+2] cycloaddition - MHAT radical cyclization
Viridin and Viridiol belong to the class of furanosteroids and were isolated from the fungal species of Gliocladium virens and Trichoderma viride.
Unsaturated ester A, accessed in four steps from l-(+)-ribose, underwent intramolecular [3+2] cycloaddition after nitrile oxide formation, affording isoxazoline B. Cobalt-catalyzed MHAT radical cyclization was used to construct the steroid skeleton of G.