CH3−CH2−CHO\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{CHO}CH3−CH2−CHO
CH3COCH3\mathrm{CH}_{3} \mathrm{COCH}_{3}CH3COCH3
CH3−CHO\mathrm{CH}_{3}-\mathrm{CHO}CH3−CHO
C6H5−CHO\mathrm{C}_{6} \mathrm{H}_{5}-\mathrm{CHO}C6H5−CHO