Approximately 30 compounds have been identified in the aroma of green tea, the major ones being benzyl alcohol, phenylethyl alcohol, a hexenol, linalool, geraniol and methyl salicylate.
The primary synthetic methods of 4-hydroxycoumarin was reviewed starting from phenol, 2-acetylsalicylic acid, methyl salicylate, and o-hydroxyacetophenone respectively.