In continuation of studying structure/activity relationships of odorous compounds, the influence of the bridgehead-bonded Me group of (+)-norpatchoulenol ( 1) and (−)-patchoulol ( 2) and the olfactory properties of the corresponding unsaturated and saturated derivatives (±) −3, (±) −4 and (±) −5, (±) −6, respectively, are studied. The key odour descriptors-wood, earth, and camphor-are used for classification.