{HEAD ~ The process} 1, wherein {TAIL ~ the first stage} is undertaken with equimolar quantities of potassium xanthate and the sodium salt of 2 bromopropionic acid 
wherein
{ HEAD ~ The process } 1 , wherein { TAIL ~ the first stage } is undertaken with equimolar quantities of potassium xanthate and the sodium salt of 2 bromopropionic acid
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH