Cascade Reaction of Barbiturate Heptafulvenes with Acetic Acid Esters.

While divergent synthesis represents a powerful tool in synthetic chemistry, achieving precise control by varying only the reaction time remains rare. Herein, we report a time-dependent cascade reaction for the synthesis of bicyclic [5.3.0]decanes and dihydronaphthyl-2-one derivatives. By simply tuning the reaction time, two distinct types of products are selectively obtained from identical substrates under identical conditions. This method features mild conditions, step economy, and broad substrate compatibility, with its synthetic potential validated by scale-up, derivatization, and late-stage functionalization.