The Diels-Alder reaction of 1,2-bis(methylene)cyclooctane (13), 4-methylenespiro[2.7]decane (29), 4-methylenespiro[2.6]nonane (40) and 4-methylenespiro[2.7]dec-8-ene (46) with different a,b-unsaturated carbonyl compounds afforded various derivatives 16, 18, 20, 22, 24, 26, 32, 36, 38, 41, 42 and 47 of a molecular-modeled lead compound 9. These less flexible b-ionone-mimics with bicyclo[6.4.0]dodecene and bicyclo[5.4.0]undecene skeletons possess interesting fruity-woody-floral odor notes and provide insight into the structure-odor correlation of violet odorants. 5-(2-Methylcycloalk-1-en-1-yl)hex-3-en-2-ones (e.g. 35) were identified as byproducts of the Rh(I)-catalyzed reactions of the vinylcyclopropanes 29 and 40.