Synthesis of Benzo-15-crown-5 polyethers, anticoccidial ionophore analogues

Synthesis of eight benzo-15-crown-5 derivatives I (R = H, CO2Me, CO2H, Me; R1 = H, CO2H, CO2Me, CHO, CH=CHCO2H, CH2CH2CO2H) designed as rigid cyclic analogues of the anticoccidial ionophores is described. No anticoccidial activity was observed in chickens, but moderate activity in tissue culture was found for I (R = Me, R1 = H; R = R1 = H) and dibenzo-18-crown-6.