Coumarin

The postulated mechanism for the reaction of coumarin 4 as an antioxidant, as indicated in Fig 3, relies on the mercapto hydrogen atom (bold), which is under the influence of resonance and inductive effects.

Coumarin's spicy, balsamic, and sweet vanilla scent is valued by perfume and flavor industries, but it may also add a hint of tobacco to a perfume blend or enhance lavender in a scent.