Aldehydes Nomenclature 3 3-methylpentanal The aldehyde carbon is number 1. IUPAC:Replace -e with -al. Chapter 18 6Chapter 18 6 CH3 CH2 CH CH3 CH2 C H O Aldehydes Nomenclature ▪ The aldehyde carbon is number 1. ▪ IUPAC: Replace -e with -al. 3-methylpentanal 1 2 3 5