Indene is an inherently difficult molecule to functionalize at its C (2) position. A number of synthetic strategies to prepare 2-substituted indenes have been developed,'and among these various approaches, the introduction of the C-2 substituent generally precedes the indene ring formation.? Along these lines, we have found that the application of a 4+ 1 approach to indan ring construction has resulted in an improved synthesis of 2-( ...
