The role of monomer in alkylation reactions of the lithium enolate of p-phenylisobutyrophenone in tetrahydrofuran

The lithium enolate of p-phenylisobutyrophenone in tetrahydrofuran (THF) exists as tetramer contact ion pairs at higher concentrations although there is still a significant level of the monomeric form. Alkylation reaction studies using a variety of alkylating agents reveal that this reaction is first order based on the concentration of the monomer in THF. This suggests that the monomer is the reactive species in alkylation reactions.