Common Names Named as substituted acetylene. CH3C≡CH methylacetylene (terminal alkyne) CH3 CH3 CH3一CH-CH2C=CCH-CH3 isobutylisopropylacetylene (internal alkyne) Chapter 9 7Chapter 9 7 Common Names Named as substituted acetylene. CH3 C CH methylacetylene (terminal alkyne) CH3 CH CH3 CH2 C C CH CH3 CH3 isobutylisopropylacetylene (internal alkyne) =>