Determination of Absolute Configuration of α-Hydroxyphosphonates by 31P NMR Spectroscopy of Corresponding Mosher Esters

Article abstract of DOI:10.1016/S0040-4020(01)81758-0

(R)-MTPA esters of α-hydroxyphosphonates 1a-h of known absolute configuration were prepared and their 31P NMR spectra were recorded.The chemical shifts of the 31P signals of the derivatized (S)-alcohols are consistently downfield relative to the signals of the corresponding (R)-alcohols.A variety of racemic and diastereomeric α-hydroxyphosphonates 1i-o and their (R)-MTPA esters were prepared.The 31P chemical shift differences are large enough to securely assign absolute configurations to α-hydroxyphosphonates.