Synthesis of bone-targeted oestrogenic compounds for the inhibition of bone resorption

Syntheses have been realised for several members of a new class of potential bone resorption inhibitors consisting of steroidal oestrogenic compounds linked at the 17 position to a geminal bis(phosphonic acid) moiety through an ester linkage. The approach used has the potential to allow other biologically active compounds to be coupled to the geminal bisphosphonate unit.