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