1,1-bis(diethylphosphono)ethylene
3,5-di(tetraethyl ethylamino-2,2-bisphosphonate)benzoic acid
tetraethyl 3-carboxypropylene-1,1-bisphosphonate
tetraethyl [3,3-bis(benzyloxylcarbonyl)propylideno]bisphosphonate
tetraethyl (17β (3-benzyloxyoestra-1,3,5(10)-trienyl)oxycarbonyl) (methyloxycarbonyl) propylene bisphosphonate