Mạch hở thôi nha em
\(C{H_2} = CH - C{H_2} - C{H_2} - C{H_3}\) pent-1-en
\(C{H_3} - CH = CH - C{H_2} - C{H_3}\) có đồng phân hình học
cis / trans pent-2-en
\(C{H_2} = C(C{H_3}) - C{H_2} - C{H_3}\): 2-metyl but-1-en
\(C{H_3} - C(C{H_3}) = CH - C{H_2}\): 2-metyl but-2-en
\(C{H_3} - CH(C{H_3}) - CH = C{H_2}\): 3-metyl but-1-en