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