Abstract High enantioselectivity (up to 97% ee) have been achieved in the protonation of samarium enolates which were generated by SmI 2-mediated cross-coupling reaction between unsymmtrical dialkylketene and allyl iodide, using a C 2-symmetric chiral diol as a proton source. The stereochemistry of enolate formation and of the enantioselective protonation is discussed.
