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