{HEAD ~ R2} and R3, together with {TAIL ~ the carbon atom} to which they are bonded, are a cyclopropylidene, cyclobutylidene, cyclopentylidene, or cyclohexylidene 
{ HEAD ~ R2 } and R3 , together with { TAIL ~ the carbon atom } to which they are bonded , are a cyclopropylidene , cyclobutylidene , cyclopentylidene , or cyclohexylidene
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH