Methylation of damnacanthal with diazomethane gave a methyl ketone derivative, while methylation with dimethyl sulfate and anhydrous potassium carbonate gave a monomethy ether and munjistin dimethyl ether (m.p. 263∼265°), and methylation with methyl iodide and silver oxide gave a trimethyl ether. The infrared absorption spectra of these methyl derivatives and other derivatives of damnacanthal were measured.
