A new Horner-Wadsworth-Emmons type coupling reaction between nonstabilized β-hydroxy phosphonates and aldehydes or ketones

Treatment of nonstabilized beta-hydroxy phosphonic acid mono methyl esters with diisopropyl carbodiimide at ambient temperature leads to clean stereospecific elimination. The phosphonic acid mono alkyl esters are accessible by the selective partial saponification of dimethyl or diethyl alkyl phosphonates with NaOH or MgBr2. Isolated yields over both hydrolysis and elimination steps average 55-75%.