R7 is OH, lower alkyl, phenyl, benzyl, {TAIL ~ R3 phenyl} or {HEAD ~ R3 benzyl} 
R7 is OH , lower alkyl , phenyl , benzyl , { TAIL ~ R3 phenyl } or { HEAD ~ R3 benzyl }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD