Ketones and aldehydes as substituents Ther-c=o as a substituent is an acyl group is used with the suffix -yl from the root of the carboxylic acid CH,CO: acetyl: CHO: formyl CkH CO: benzoyl The prefix oxo-is used if other functional groups are present and the aou ably bonded oxygen is labeled as a substituent on a parent chainKetones and Aldehydes as Substituents: • The R–C=O as a substituent is an acyl group is used with the suffix -yl from the root of the carboxylic acid –CH3CO: acetyl; CHO: formyl; C6H5CO: benzoyl • The prefix oxo- is used if other functional groups are present and the doubly bonded oxygen is labeled as a substituent on a parent chain