From the wood of Aniba firmula Mez there were isolated benzoic acid, 4-methoxy-6-piperonyl-α-pyrone (4-methoxyparacotoin) and 4-methoxy-6-(β-styryl)-α-pyrone (5,6-dehydrokavain). This latter compound, isolated for the first time from a natural source, has been known by synthesis since 1939. The relationship to the previously described arylpyrones from other plants of the same genus and to the styrylpyrones from kava root is pointed out. Aniba firmula (Sees et Mart.) Mez (family Lauraceae) is a tree closely related to the two species of rosewood studied in former articles, with fragrant wood used in popular perfumery and a wide geographical distribution in South America; the material investigated was collected in the vicinity of Rio de Janeiro. The third compound, greenish yellow crystals (C₁₄H₁₂O₃, m.p. 138-140°), appeared new. Its structure was established as 4-methoxy-6-(β-styryl)-α-pyrone via spectral similarity to known pyrones, chemical reactions (oxidation to benzoic acid, alkaline cleavage to cinnamic acid, salt formation with loss of methoxyl, degradation to cinnamoylacetone identified by comparison with a synthetic specimen), and comparison with a synthetic sample (synthesized by Z. Macierewicz in 1939), proving identity. Thus, the new compound from Aniba firmula is 5,6-dehydrokavain, related to arylpyrones from rosewood and styrylpyrones/styryldihydropyrones from kava root.