{HEAD ~ R14} is hydrogen, nitro, {TAIL ~ cyano} or C1 4 alkylcarbonyl; and 
is
{ HEAD ~ R14 } is hydrogen , nitro , { TAIL ~ cyano } or C1 4 alkylcarbonyl ; and
HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH