Fluorination of Hydroxyesters with N,N‐Diethyl‐1,1,2,3,3,3‐Hexafluoro Propaneamine

The reactions of N,N‐diethyl‐1,1,2,3,3,3‐hexafluoro propaneamine (PPDA) with Β‐hydroxyl esters gave their corresponding fluorides. For example, methyl (S)‐(+)‐3‐fluorobutyrate was obtained from the reaction of methyl (R)‐(‐)‐3‐hydroxybutyrate with PPDA. The reaction of a ‐hydroxy esters with PPDA gave a mixture of their corresponding fluorides and 2,3,3,3‐tetrafluoropropionate esters. However, γ ‐ and δ‐hydroxyesters did not give their fluorinated compounds. Hydrolysis of those racemic monofluoroesters with Lipase MY gave optical active monofluorocarboxylic acids and esters.