CH3CHO\mathrm{CH}_{3} \mathrm{CHO}CH3CHO
(H2C)2−CH2OH\left(\mathrm{H}_{2} \mathrm{C}\right)_{2}-\mathrm{CH}_{2} \mathrm{OH}(H2C)2−CH2OH
(H3C)2COH−CH3\left(\mathrm{H}_{3} \mathrm{C}\right)_{2} \mathrm{COH}-\mathrm{CH}_{3}(H3C)2COH−CH3
(H3C)2COOH\left(\mathrm{H}_{3} \mathrm{C}\right)_{2} \mathrm{COOH}(H3C)2COOH