Stereochemical studies on some vic-bisphosphonates

Abstract

The erythro- and racemic threo-forms of tetramethyl 1,2-dihydroxyethane-1,2-diylbisphosphonate have been identified and characterised by NMR analysis of their 2-ethoxy-1,3-dioxolane derivatives and by their independent conversion into tetramethyl cis- and trans-ethene-1,2-diylbisphosphonates respectively. Optimal conditions for the partial cis-reduction of tetraethyl ethyne-1,2-diylbisphosphonate have been identified. NMR data for the AA′XX′ spectra of this range of two-carbon gem- and vic-bisphosphonates are provided and discussed.