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