{HEAD ~ The process} 11 wherein {TAIL ~ at least one group R3} is a group of the formula ##STR16## 
wherein
{ HEAD ~ The process } 11 wherein { TAIL ~ at least one group R3 } is a group of the formula # # STR16 # #
HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH