Enzyme catalysed transesterification of aminophosphonic acids .2. Isothreonine-P analogues

In this work, we used lipases to resolve kinetically the four possible configurations of an important aminophosphonic acid: isothreonine-P (isoTHR-P). We synthesized a diastereomeric mixture of N-Cbz-isoTHR-P(O)(OEt)(2) and also each diastereomer of isoTHR-P(O)(OEt)(2). Several enzymatic reactions were then performed (hydrolysis and transesterification) with these compounds. The lipases used (mainly Pseudomonas fluorescens and Candida rugosa) proved to be diastereoselective and chimioselective, but no enantioselectivity was observed.