The alkylation of 2-methylcyclopentane-1,3-dione (A) with 2-(1-naphthyl)ethyl bromide gives only the O-alkylation product. Mixtures of C- and O-alkyl derivatives are obtained with (A) when phenacyl or 1-naphthacyl bromide is employed. The C- to O-alkyl ratio is lower with (A) than with the homologous diketone 2-methyl-cyclohexane-1,3-dione; a possible explanation for this difference is advanced.
Some Alkylations of 2-Methylcyclopentane-1,3-diones
Rosenthal, D., & Davis, K. H. (1966). Some Alkylations of 2-Methylcyclopentane-1,3-diones. Journal of the Chemical Society C: Organic Chemistry, 1966, 1973-1976. https://doi.org/10.1039/J39660001973