R9 is {TAIL ~ hydrogen}, alkyl of {HEAD ~ 1 6 carbon atoms}, or aralkyl of 7 10 carbon atoms 
R9 is { TAIL ~ hydrogen } , alkyl of { HEAD ~ 1 6 carbon atoms } , or aralkyl of 7 10 carbon atoms
OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH