ORGANIC CHEMISTRY Chapter 7 o The rings of cycloalkenes containing five carbon atoms or fewer exist only in the cis form H H H H H Cyclopropene Cyclobutene Cyclopentene Cyclohexene Department of Chemistry, Xiamen UniversityORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 7 The rings of cycloalkenes containing five carbon atoms or fewer exist only in the cis form. H H H H H H H H Cyclopropene Cyclobutene Cyclopentene Cyclohexene