and the epimeric dihydroguaiols in the presence of many acidic dehydrating agents has been studied and the products characterized by GLC, spectroscopic analysis and by chemical transformations. The most interesting dehydration products are Bates' guaioxide (VIIIa, VIIIb) obtained by perchloric acid-acetic acid dehydration of guaiol (I); a methyl ketone (XIII) having a novel skeleton, obtained by the
Guaioxide is a saturated sesquiterpene oxide, for which four possible structures have been suggested. Attempted microbial hydroxylation of the compound was successful, this led to a way to open its oxide linkage under mild conditions, and to a decision of the stereochemistry II for guaioxide.