R11 and {HEAD ~ R12} are each, independently, hydrogen, alkyl of 1 6 carbon atoms, aralkyl of 7 10 carbon atoms, cycloalkyl of 3 8 carbon atoms, halogen, or {TAIL ~ trifluoromethyl} 
R11 and { HEAD ~ R12 } are each , independently , hydrogen , alkyl of 1 6 carbon atoms , aralkyl of 7 10 carbon atoms , cycloalkyl of 3 8 carbon atoms , halogen , or { TAIL ~ trifluoromethyl }
OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL