Scheme I describes {HEAD ~ the synthesis} of {TAIL ~ the 5 cycloalkenyl} analogues 3, 4 and 5 
of
Scheme I describes { HEAD ~ the synthesis } of { TAIL ~ the 5 cycloalkenyl } analogues 3 , 4 and 5
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH