Influence of light on coumarins of the khellactone group

Summary The results of experiments on the UV irradiation of six coumarins and the study of the products formed have shown that acylated derivatives of khellactone undergo photolysis with the successive splitting out of acyl residues at C₄, and then at C₃, followed by the dehydration of the resulting diol and the formation of 3-hydroxyseselin. The hypothesis has been put forward that dihydrocoumarins containing a more voluminous substituent in the 4 position are the most sensitive to light.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 614–617, September–October, 1973.