Novel Ylidic Phosphoryl Compounds from Halogenated Furan-2,5-Diones with Trivalent Phosphorus Esters: Application of this Approach to New Trisphosphonates Containing a Geminal Bisphosphonate Unit

The reactions of trivalent phosphorus esters, including trialkyl phosphites, dialkyl phosphonites, and alkyl phosphinites, with 3-halo- and 3,4-dihalo-furan-2,5-diones has been shown to lead to the formation of novel phosphorus ylides possessing additional phosphoryl-containing groups. For the reaction of 3,4-dihalo-furan-2,5-diones with trialkyl phosphites, the products are trialkoxyphosphonium ylides containing an adjacent geminal bisphosphonate unit. These can be used to provide a convenient route to novel 2,3,3-tris(dialkoxyphosphoryl)-substituted propionate esters which can be hydrolyzed to give the corresponding novel trisphosphonic monocarboxylic acid.