AMBIDENT REACTIVITY OF MEDIUM-RING CYCLOALKANE-1,3-DIONE ENOLATES

Cycloalkane-1,3-diones with ring sizes 7-10 have been converted to the ir enolates and subjected to a variety of ethylation and methylation r eagent/solvent systems. The greatest amount of O-alkylation was encoun tered using ethyl tosylate in HMPA. The O/C alkylation ratios decrease d with almost every reagent/solvent system as the ring size was increa sed. This trend is consistent with greater steric strain in the conjug ated enolate resonance contributor, resulting in diminished O-attack a s the ring size is increased.