Herein, a new, bio-mass derived sustainable feedstock was employed for the synthesis of 4H-pyran derivatives. In context of this, water extract of tamarindus indica seed ash (WETSA) has been proven as a reaction media for one-pot three-component reaction between C−H activated carbonyl compound, aryl aldehyde, and malononitrile which acts as a basic catalyst. This novel method offers several advantages such as simple work-up, excellent yield, short reaction time, green reaction conditions, and the reaction even proceeds smoothly without any external promoter. The catalyst was recycled up to four times without significant loss in catalytic activity.