Conjugate addition reaction of achiral methyl 2-(N-benzylamino)-1-cyclohexenecarboxylate 2 to chiral acrylates 4a,4b,4c led, after treatment of the primary adducts with sodium methoxyde, to α,α-disubstituted β-keto ester 1 with high enantiomeric excesses.
Hervouet, K., & Guingant, A. (1996). Highly diastereoselective addition of methyl 2-(N-benzylamino)-1-cyclohexenecarboxylate to chiral acrylates. Tetrahedron Asymmetry, 7(2), 425–426. https://doi.org/10.1016/0957-4166(96)00024-9