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
Castor wax it contains three secondary hydroxyl groups. These coating compositions are useful as a top coat varnish for leather, wood and rubber. Castor wax can also be added to beeswax for encaustic painting. Castor wax Castor wax, also called hydrogenated castor oil, is an opaque, white vegetable wax. It is produced by the hydrogenation of pure castor oil often in the presence of a nickel catalyst to increase the rate of reaction. The hydrogenation of castor oil forms saturated molecules of castor wax; this saturation is responsible for the hard, brittle and insoluble nature of the wax. Castor wax is used