reacting {TAIL ~ the cellulose activate} with an acetylating agent in {HEAD ~ the presence} of the acetylating catalyst and acetylating solvent, 
reacting { TAIL ~ the cellulose activate } with an acetylating agent in { HEAD ~ the presence } of the acetylating catalyst and acetylating solvent ,
OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH