2-Hydroxy-4, 6-dimethoxycrotonophenone (1), isolated from the plant Dysophylla stellata Benth. by Joshi and Ravindranath,1 is the only example of an open chain form of chromanones. The co-occurrence of the crotonophenone (1) with chromone and butyrophenone1 suggests that these are biogenetically related in the same way as chalcones are to flavonoids.2 It is likely that more crotono-phenones and 2-methylchromanones will be discovered in nature.
A. Banerji, Goomer, N. C., and Kalena, G. P., “Synthesis of 2-Hydroxy-4, 6-Dimethoxycrotonophenone A New Class of Natural Products from Dysophylla Stellata Benth”, Synthetic Communications, vol. 10, pp. 851–856, 1980.