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