Synthesis of stereochemically-biased spiropyrans by microwave-promoted, one-pot alkylation-condensation.

A microwave-assisted, two-step, one-pot synthesis of spiropyrans has been developed. This process was used to synthesise a range of sterically-congested spiropyrans from readily available precursors, employing environmentally benign solvents. The unusual substituent pattern possessed by these structures has been shown to influence the stereoselectivity of spiropyran ring-closure.