By selective chemical reactions we mean reactions of a compound or polymer containing two different functional groups with {HEAD ~ a reagent} which reacts only or predominantly with one of the said functional groups, leaving the other functional group free to take part in {TAIL ~ a subsequent chemical reaction} 
By selective chemical reactions we mean reactions of a compound or polymer containing two different functional groups with { HEAD ~ a reagent } which reacts only or predominantly with one of the said functional groups , leaving the other functional group free to take part in { TAIL ~ a subsequent chemical reaction }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH 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 OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL