Salicylaldehyde be prepared from the corresponding phenol by the Duff reaction, or by treatment with paraformaldehyde in the presence of magnesium chloride and a base. Salicylaldehyde was identified as a characteristic aroma component of buckwheat. It is also one of the components of castoreum, the exudate from the castor sacs of the mature North American beaver ("Castor canadensis") and the European beaver ("Castor fiber"), used in perfumery. Furthermore, salicylaldehyde occurs in the larval defensive secretions of several leaf beetle species that belong the subtribe Chrysomelina. An example for a leaf beetle species that produces salicylaldehyde is the red poplar leaf beetle
Hyraceum and ages until it becomes a fairly sterile, rock-like material (also referred to as "Africa Stone") that contains compounds giving it an animal, deeply complex fermented scent that combines the elements of musk, castoreum, civet, tobacco and agarwood. The material is harvested without disturbing the animals by digging strata of the brittle, resinous, irregular, blackish-brown stone; because animals are not harmed in its harvesting, it is often an ethical substitute for deer musk and civet, which require killing or inflicting pain on the animal. After it has been fossilized hyraceum has been used as a traditional folk medicine in South