Homologations and chain extensions
The reaction of β-keto esters with CF3CO2ZnCH2I provided the corresponding chain-extended products in moderate to good yields. α-Substituted acyclic β-keto esters reacted less efficiently than cyclic β-keto esters or simple β-keto esters.
S. Xue, Y.-K. Liu, L.-Z. Li, Q.-X. Guo, J. Org. Chem., 2005, 70, 8245-8247.
The conversion of β-keto esters into β-methylated and phenylated γ-keto esters can be achieved through treatment with zinc carbenoids derived from 1,1-diiodoethane and diiodotoluene, respectively.
W. Lin, R. J. McGinness, E. C. Wilson, C. K. Zercher, Synthesis, 2007, 2404-2408.