The compounds of {HEAD ~ this invention} wherein {TAIL ~ R} is OH can be attached to a biomolecule indirectly through a phosphoramidite ultimately forming a phosphate linkage 
wherein
The compounds of { HEAD ~ this invention } wherein { TAIL ~ R } is OH can be attached to a biomolecule indirectly through a phosphoramidite ultimately forming a phosphate linkage
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH