The structure of laricinolic acid and its biomimetic transformation into officinalic acid

Abstract

Laricinolic acid (8), a new sesquiterpene of the drimane type, has been isolated from the wood-rotting fungus Laricifomes officinalis. Its structure was elucidated by spectroscopic means and confirmed via a correlation with the known drimenine derivative 13. Oxidation of 8 to 1, followed by a mild thermal treatment, furnished (−)-officinalic acid (4) in 65% yield. This transformation establishes the hitherto unknown absolute configuration of the latter. An independent correlation was achieved by pyrolysis of 4 which furnished (−)-dihydrooxoisodrimenine (14) of known absolute configuration.