Cyclic Alkene Compounds cyclohexene cyclooctene trans-cyclodecene cis-cyclodecene Copyright2010 Pearson Prentice Hall,Inc. Trans cycloalkenes are not stable unless the ring has at least eight carbons. Cycloalkenes are assumed to be cis unless otherwise specifically named trans.Cyclic Alkene Compounds ❖Trans cycloalkenes are not stable unless the ring has at least eight carbons. ❖Cycloalkenes are assumed to be cis unless otherwise specifically named trans