CERATIOLIN FROM CERATIOLA ERICOIDES

The title compound, 3-phenyl-1-(2,4,5-trihydroxy-3,5-dimethyl-6-oxo- 1 ,5-cyclohexadienyl)-1-propanone, was confirmed to be a dihydrochalcone containing a fully substituted cyclohexadienone ring. This ring has a flattened half-chair conformation, with the dione C atom 0.203 (1) An gstrom out of the diene plane and the tetrahedral C atom 0.184(1) Angs trom to the opposite side of the plane. The hydroxy substituent on the tetrahedral C atom forms an intramolecular hydrogen bond to the carbo nyl O atom of the cyclohexadienone, having an O...O distance of 2.658 (1) Angstrom and an angle at H of 116(2)degrees. One of the other hydr oxy substituents forms an intramolecular hydrogen bond with the carbon yl O atom of the beta-phenylpropionyl group, having an O...O distance of 2.414 (2) A and an angle at H of 160 (2)degrees.