Coumarin

Coumarin is a fragrant organic chemical compound in the benzopyrone chemical class, although it may also be seen as a subclass of lactones. It is a natural substance found in many plants, and a colorless crystalline substance in its standard state.

The name comes from a French term for the tonka bean, coumarou, one of the sources from which coumarin was first isolated as a natural product in 1820. It has a sweet odor, readily recognised as the scent of newly-mown hay, and has been used in perfumes since 1882.(source)