The synthesis and spectra (ultraviolet, infrared, and nuclear magnetic resonance) of some previously unknown 2,n-dibenzylidene and dicinnamylidenecyclanones where n = 5–10 are described. The spectra are in accord with the expected decrease in coplanarity of the conjugated groups with increasing ring size. trans-Ring hydrogen bonding may occur in 2,10-dibenzylidenecyclodecanone but no evidence is found for this effect in the parent cyclanone.