Ancol $C_4H_8(OH)_2$ là ancol no, 2 chức, mạch hở.
Các CTCT:
(1) $CH_2OH-CH(OH)-CH_2-CH_3$
(butan-1,2-điol)
(2) $CH_2OH-CH_2-CH(OH)-CH_3$
(butan-1,3-điol)
(3) $CH_2OH-CH_2-CH_2-CH_2OH$
(butan-1,4-điol)
(4) $CH_3-CH(OH)-CH(OH)-CH_3$
(butan-2,3-điol)
(5) $CH_2OH-CH(CH_3)-CH_2OH$
(2-metylpropan-1,3-điol)
(6) $(CH_3)_2C(OH)-CH_2OH$
(2-metylpropan-1,2-điol)