1,8-Dimethyl-4-isopropenylspiro[4.5]dec-7-ene

(1R,4S,5S)-1,8-dimethyl-4-prop-1-en-2-yl-spiro[4.5]dec-8-ene

(1R,4S,5S)-1,8-Dimethyl-4-(1-methylethenyl)spiro[4.5]dec-7-ene