Highly stereoselective anti SN2' substitutions of (Z)-allylic pentafluorobenzoates with polyfunctionalized zinc-copper reagents.

[reaction: see text] Allylic substitution reactions of zinc-copper organometallics on (Z)-allylic pentafluorobenzoates proceed with very high regioselectivity and excellent anti selectivity. The high fidelity in transfer of stereochemical information allowed a short synthesis of (+)-ibuprofen (97% ee).