Systematic names for aldehydes are obtained by replacing -e with-al. An aldehyde has to be at the end of a chain,and therefore it is carbon number 1. 0 CHg-C-H H3C-CH2-CH=CH-CHO ethanal pent-2-enal If the aldehyde is attached to a large unit,the suffix-carbaldehyde is used. CHO cyclohexanecarbaldehyde Chl8 Ketones and Aldehydes(landscape) Page 4Ch18 Ketones and Aldehydes (landscape) Page 4 Systematic names for aldehydes are obtained by replacing -e with -al. An aldehyde has to be at the end of a chain, and therefore it is carbon number 1. If the aldehyde is attached to a large unit, the suffix -carbaldehyde is used. CH3 C H O H3C CH2 CH CH CHO ethanal pent-2-enal CHO cyclohexanecarbaldehyde