Esters () are named as alkyl derivatives of carboxylic acids. The alkyl (R') group is named first. The  part is then named as a separate word based on the carboxylic acid name, with the ending changed from "-oic acid" to "-oate" or "-carboxylate" For example,  is methyl pentanoate, and  is ethyl 4-methylpentanoate. For esters such as ethyl acetate (), ethyl formate () or dimethyl phthalate that are based on common acids, IUPAC recommends use of these established names, called [http://www.acdlabs.com/iupac/nomenclature/93/r93_511.htm retained names]. The "-oate" changes to "-ate." Some simple examples, named both ways, are shown in the figure above.
If the alkyl group is not attached at the end of the chain, the bond position to the ester group is suffixed before "-yl":  may be called butan-2-yl propanoate or butan-2-yl propionate.. The prefix form is "oxycabonyl-" with the (R') group preceding.