Results in Chemistry (Jan 2022)
A green protocol for one-pot synthesis of 3,4-dihydropyrano[c]chromenes and biscoumarins by employing WEB as an internal base
Abstract
A simple, mild and environmentally benign methodology has been developed for the synthesis of 3,4-dihydropyrano[c]chromenes and biscoumarins using water extract of banana peel ash (WEB) as a natural base under ultrasound (US) irradiation. Interestingly, addition of ethanol as a co-solvent improved the yield of desired products. This agro-waste based protocol has simple workup procedure and column-free purification with no need of external base to facilitate the reaction.