alcan cu 4 at C
CH3-CH2-CH2-CH3 CH3-CH-CH3
CH3
n-butan 2-metilpropan (izobutan)
alchena cu 4 at. C
CH2=CH-CH2-CH3 CH2=C-CH3
CH3
1-butena 2-metilpropena (izobutena)
CH3-CH=CH-CH3
2-butena
izomerii de pozitie ai hexenei
CH2=CH-CH2-CH2-CH2-CH3
1-hexena
CH3-CH=CH-CH2-CH2-CH3
2-hexena
CH3-CH2-CH=CH-CH2-CH3
3-hexena