IHD = 1 Therefore there can be only 1 -bond or ring. The two signals composed of singlets means all the hydrogens are isolated from one another, but there are two types in the molecule giving differing chemical shifts. The structure must be symmetrical. Likely compound is 2,2- dimethylpropanal (three methyl groups contributing one signal, and one aldehyde hydrogen contributing another signal. All non-equivalent hydrogens are too far apart to split the signal, resulting in singlets) Solution IHD = 1 Therefore there can be only 1 -bond or ring. The two signals composed of singlets means all the hydrogens are isolated from one another, but there are two types in the molecule giving differing chemical shifts. The structure must be symmetrical. Likely compound is 2,2- dimethylpropanal (three methyl groups contributing one signal, and one aldehyde hydrogen contributing another signal. All non-equivalent hydrogens are too far apart to split the signal, resulting in singlets).