One form of these compounds is produced by the disproportionation of aldehydes in the Tischenko reaction. A mild reducing agent used in transfer hydrogenations of imines is named for Arthur Hantzch and this functional group. In the Yamaguchi (15[1])reaction, TCBC forms an anhydride that is then catalyzed by DMAP to form this (-5[1])functional group. Polymers with this functional group can be formed from DMT and ethylene glycol. The (*) Dieckmann cyclization reacts one of these (10[1])compounds to produce their “beta-keto” type. Cyclic forms of these compounds are known as (-5[1])lactones. Refluxing a carboxylic acid with an alcohol produces one of these compounds in a reaction named for (10[1])Fischer. For 10 points, name this functional group with general formula R-C-O-O-R-prime and a fruity aroma. (10[1])■END■