{HEAD ~ The acyl substituent} in {TAIL ~ the 10 position} may also be substituted with electron donating groups so long as the acyl substituent is electron withdrawing overall 
{ HEAD ~ The acyl substituent } in { TAIL ~ the 10 position } may also be substituted with electron donating groups so long as the acyl substituent is electron withdrawing overall
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH