The reaction of {TAIL ~ a compound} of formula IV with {HEAD ~ a compound} of formula V in accordance with process variant can be carried out in a manner known per se 
The reaction of { TAIL ~ a compound } of formula IV with { HEAD ~ a compound } of formula V in accordance with process variant can be carried out in a manner known per se
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH