Phosphonate-Phosphate- and Phosphate-Phosphonate-Rearrangement and Its Application, Part II: Stereochemistry of Phosphonate-Phosphate-Rearrangement at Carbon as Exemplified by the Isomerisation of (R)-(+)- and (S)-(-)-(1-Hydroxy-1-phenylethyl)phosphonic Acid Diethylester

Article abstract of DOI:10.1007/BF00814152

The phosphonate-phosphate-rearrangement of (R)-(+)- and (S)-(-)-6 was investigated at room temperature in various organic solvents and mixtures of organic solvent and of up to 7percent of water , using potassium t-butoxide, potassium hydroxide, and DBU as bases.The rearrangement is shown to occur with retention of configuration at carbon.The highest enantiomeric excess (10.7percent) for phosphate 8 was observed using a mixture of DMSO and water (100:7) containing DBU as base.Under these conditions the cleavage of phosphonate 6 into acetophenone and phosphite predominates and the yield of phosphate 8 is only 7.7percent. - Keywords.Stereochemistry; Phosphonate-phosphate-rearrangement; DMSO; DBU.