A compound 3 wherein {HEAD ~ R2} is {TAIL ~ hydrogen}, R4 and R5 are hydrogen or methyl, and X is hydrogen, fluoro or chloro 
is
A compound 3 wherein { HEAD ~ R2 } is { TAIL ~ hydrogen } , R4 and R5 are hydrogen or methyl , and X is hydrogen , fluoro or chloro
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH