Synthesis of (+)-juruenolide c: use of sequential 5-exo-digonal radical cyclization, 1,5-intramolecular hydrogen transfer, and 5-endo-trigonal cyclization.
Acetylenic alcohol 10 was converted successively into silane 11 and phenylseleno carbonate 14. On treatment with Ph3SnH, the latter underwent 5-exo-digonal radical cyclization, intramolecular hydrogen transfer, and 5-endo-trigonal cyclization, yielding 15. Conversion of the lactone into the lactol benzyl ether 17, carbon-silicon bond cleavage, and regeneration of the lactone carbonyl gave (+)-juruenolide C (1).
Clive
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Chemistry Department, University of Alberta, Edmonton, Alberta T6G 2G2, Canada. derrick.clive@ualberta.ca
Ardelean
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D000935:Antifungal Agents / Q000138:chemical synthesis*; D004149:Dioxoles / Q000138:chemical synthesis*; D007783:Lactones / Q000138:chemical synthesis*; D009904:Optical Rotation; D010946:Plants, Medicinal / Q000737:chemistry; D013237:Stereoisomerism
D000935:Antifungal Agents; D004149:Dioxoles; D007783:Lactones; C437388:juruenolide C