This application discloses a novel process for the preparation of phosphonate esters useful as intermediates in the preparation of himbacine analogs, themselves useful as thrombin receptor antagonists. The chemistry taught herein can be exemplified by the following scheme: wherein R9 is selected from alkyl, aryl heteroaryl and arylalkyl groups having 1 to 10 carbon atoms, and R11 is selected independently for each occurrence from alkyl, aryl heteroaryl and arylalkyl groups having 1 to 10 carbon atoms and hydrogen, X2 is Cl, Br, or I; X3 is selected from Cl and Br; and PdLn is a supported palladium metal catalyst or a soluble heterogeneous palladium catalyst. The L-derivatizing reagent is a moiety which converts the alcohol functional group of compound 137D to any leaving group which can be displaced by a triorgano-phosphite phosphonating agent.