Synthesis of Novel Functionalized gem-Bisphosphonates.-Michael-type addition of the masked polyfunctional nucleophiles (II) to tetraethyl ethylidenebisphosphonate (I) produces the gem-bisphosphonates (III). The compounds (IIIb) and (IIId) are deprotected yielding the primary amines (IV). The carboxylic acid (V) is obtained by ester saponification of (IIIa) followed by thermal decarboxylation of the dicarboxylic acid formed. Reaction of potassium cyanide (VI) with (I) gives 3,3-bis(diethoxyphosphoryl)propionitrile (VII). The compounds (III) -(V), and (VII) are potentially useful in the therapy of bone tissues. -(STURTZ, G.; GUERVENOU, J.; Synthesis (1991) 8, 661-662; Lab. Chim. Heteroorg., UFR Sci. Techn., 29287 Brest, Fr.; EN)
The preparation of a.P unsaturated monophosphonate heterocycles is reported. 9-diethylphosphono-7-oxabicyclo[4.3.0]non-1(9)-ene, some 3-diethylphosphono-2H-1-benzopyrans and 2-diethylphosphono-3H-naphtol[2,1-b]pyran have been prepared from tetraethyl ethylidene gem-bisphosphonate and 2-hydrocyclohexanone, substituted salicylaldehydes or 2-hydroxy-1-naphthaldehyde respectively.
Synthesis of Diethylphosphono-Substituted 2,5-Dihydrofuran, 2H-1-Benzopyrans and 3H-Naphtho(2,1-b)pyran.-The addition of alcohols to the gem-bisphosphonate (II) occurs fast giving ethers the stability of which depends on the electronic environment of the oxygen. Starting from alcohols such as (IV) and (VI) intramolecular Horner-Emmons reactions lead to α,β-unsaturated monophosphonate heterocycles such as (V) and (VII). -(GUERVENOU, J.; STURTZ, G.; Phosphorus, Sulfur Silicon Relat.
2002organo-phosphorus compounds organo-phosphorus compounds S 0080
-171Synthesis of (±) Ethyl 2,2-Bis(diethoxyphosphoryl)cyclopropane Carboxylates.-5 Cyclopropane derivatives of type (III) are prepared by a Michael-type addition followed by intramolecular cyclization.
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