[(C2H5O)2P(O)CHPHLI.N(CH2CH2)3N]-INFINITY - SOLID-STATE STRUCTURE, AGGREGATION IN THF SOLUTION, AND MODEL-CALCULATIONS ON THE STRUCTURE OF A WADSWORTH-HORNER-EMMONS REAGENT

The X-ray structure determination of the lithiated Wadsworth-Horner-Emmons reagent (C2H5O)2P(O)CHPhLi (2) reveals a crystal structure with [(C2H5O)2P(O)CHPhLi.N(CH2CH2)3N]infinity layers in which the anionic (C2H5O)2P(O)CHPh units are connected to ''dimers'' by Li-O-Li-O rings. Further aggregation results from the two N(CH2CH2)3N (= DABCO) molecules at each Li. The configuration at the slightly pyramidalized benzylic anionic carbon and the conformation around the C-P bond are reproduced by ab initio calculations. Cryoscopic determinations of the aggregation in THF at -108-degrees-C reveal a dimeric (C2H5O)2P(O)CHPhLi unit.