{TAIL ~ R8} is H, OH, alkoxy, phenoxy, {HEAD ~ benzyloxy}, ##STR18## NR4 R5, lower alkyl, phenyl or R3 phenyl; R9 is O , CH2 , NH or N  
{ TAIL ~ R8 } is H , OH , alkoxy , phenoxy , { HEAD ~ benzyloxy } , # # STR18 # # NR4 R5 , lower alkyl , phenyl or R3 phenyl ; R9 is O , CH2 , NH or N
TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH 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 OTH OTH OTH OTH