The reaction of carbonyl-ene-nitrile compounds with propargyl carboxylates in the presence of a catalytic amount of PtCl2 afforded the α-alkylidene-N-furylimines with high stereoselectivities.
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. (C) 1998 Published by Elsevier Science Ltd. Ail rights reserved.