$$\begin{array}{|c|c|}
\hline
\text{CTCT}&\text{Tên gọi}\\
\hline
\rm CH_3-CH_2-CH_2-CHO&\rm Butanal\\
\hline
\rm CH_3-\mathop{C}\limits_{\Big|}\kern-0.5ptH-CHO&\rm 2-metylpropanal\\
\rm\ CH_3&\\
\hline
\rm CH_3-CH_2-CO-CH_3&\rm Butan-2-ol\\
\hline
\end{array}$$