The lichen acids, atranorin and lecanoric acid obtained fromParmelia essinica have been made the starting points for the preparation of 5-hydroxy-coumarin derivatives. 5-Hydroxy-7-methyl-coumarin has been synthesised for the first time from ethyl hæmatommate and has been shown to be different from the compound prepared by Pechmann by the action of malic acid on orcinol. The above coumarin can also be readily obtained from ethyl orsellinate and lecanoric acid. Some of its derivatives along with those of 5-hydroxy-4: 7-dimethyl-coumarin have been obtained and characterised. An improved method for the synthesis of ethyl hæmatommate is described.