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