Cis-Trans Isomerism H.C CH3 H CH3 cis-2-butene trans-2-butene CH3 H令令H H,C令H CHCH3 CH3 CH3 H CH H CH3 cis-1,2-dimethylcyclopentane trans-1,2-dimethylcyclopentane -Cis:like groups on same side of ring -Trans:like groups on opposite sides of ring Cis-Trans Isomerism ▪Cis: like groups on same side of ring ▪Trans: like groups on opposite sides of ring