By extension of the method of preparing tropolone by bromination - debydrobromination of oycloheptane-1:2-dione to isopropylcycloheptanediones, alpha-, beta-, and gamma- isopropyltropolones have been prepared and have been shown to be identical with the naturally-occurring alpha-, beta-, and gamma thujaplicins. Some reactions of tropolone have been examined, in particular, the Friedel-Crafts and Reimer-Tiemann reactions. The reduction of tropolone with lithium aluminium hydride has been studied. In the course of an attempt to prepare a gamma-nitrotropolone, cyclodecane-1:2-dione was found to dimerise. The nature of this product has been examined and a structure proposed. An attempted synthesis of gamma-tropolone is also described. PART II. ...