Cyclohexanecarboxylic acid, 3-[[(2E)-3-(3,4-dihydroxyphenyl)-1-oxo-2-propenyl]oxy]-1,4-dihydroxy-5-[ [(2E)-3-(4-hydroxy-3,5-dimethoxyphenyl)-1-oxo-2-propenyl]oxy]-, ethyl ester, (1R,3R,4S,5R)-