Lipase-catalyzed kinetic resolution of 2-acyloxy-2-(pentafluorophenyl)acetonitrile

The lipase-catalyzed kinetic resolution of (±)-2-acyloxy-2-(pentafluorophenyl)acetonitrile (±)- 1 gave optically active cyanohydrin (S)- 2 and its antipodal ester (R)- 1 ( E = 211), the former of which was transformed (TBSOTf, DMAP) into its TBS-ether (S)- 3 , a new fluorinated chiral building block, and into naproxen ester 4 for X-ray analysis to determine the absolute configuration.