Reactions of Ethyl 2-(1-Indanylidene) cyanoacetate Anion with Alkylating Agents and Aldehydes

Ethyl 2-(1-indanylidene) cyanoacetate (I) was treated with phenylmagnesium bromide and the resultant ambident anion (II) was reacted with a few alkylating agents and aldehydes. Interestingly, the alkylation reactions of the alkylidenecyanoacetate system were accompanied by γ-alkylation to a significant extent together with the preferred α-alkylation. The anion was also formed by the use of sodium hydride and subjected to the alkylation reactions. It seems that the alkylation reactions are dependent upon metal counterions yielding α-and γ-substituted products in a different proportion. Reactions of the anion with aldehydes afforded a diene (VI) and lactone (VII) which were formed as the result of an exclusive reaction at the γ-position.