ORGANIC CHEMISTRY Chapter 16 o Aldehydes are named by replacing the terminal - e of the corresponding alkane name with -al o The longest chain selected as the base name must contain the-CHO group, and the -CHo carbon is al ways numbered as carbon 1 H-C-H CH3-c-h Ch2 CHb-C-H Methanal Ethanal Propanal (Formaldehyde) (Acetaldehyde)(Propionaldehyde) CICHoCHCHoCH-C-H CkHsCHo-C-H 5-Chloropentanal Phenylethanol (Phenylacetaldehyde Department of Chemistry, Xiamen UniversityORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 16 Aldehydes are named by replacing the terminal –e of the corresponding alkane name with –al. The longest chain selected as the base name must contain the –CHO group, and the –CHO carbon is always numbered as carbon 1. O H C H O CH3 C H O CH3CH2 C H Methanal (Formaldehyde) Ethanal (Acetaldehyde) Propanal (Propionaldehyde) O ClCH2CH2CH2CH2 C H 5-Chloropentanal O C6H5CH2 C H Phenylethanal (Phenylacetaldehyde)