The Preparation of Dimethyl α -Hydroxyphosphonates and the Chemical Shift Non-Equivalence of Their Diastereotopic Methyl Ester Groups

Abstract

Dimethyl α -hydroxyalkyl-, α -hydroxybenzyl-, α -hydroxyfurfuryl-, and α -hydroxy-α -thienylmethyl-phosphonates have been prepared in good yield by the alumina-catalyzed reaction of dimethyl phosphite with the corresponding alkanals, aryl aldehydes (or aryl methyl ketones), furfuraldehyde, and 2- or 3-thiophenecarboxaldehyde, respectively, thus confirming the general utility of this synthetic procedure. The 1H and 13C nmr spectra of the products exhibit characteristic chemical shift non-equivalence of the diastereotopic methyl ester groups, for which a tentative order of non-equivalence is reported and discussed.