Cetrarin

Cetraric acid

9-ethoxymethyl-4-formyl-3,8-dihydroxy-1,6-dimethyl-11-oxodibenzo[b,e][1,4]dioxepin-7-carboxylic acid

9-(Ethoxymethyl)-4-formyl-3,8-dihydroxy-1,6-dimethyl-11-oxo-11H-dibenzo[b,e][1,4]dioxepin-7-carboxylic acid