75364-14-6 Naphthaceno(2,3-b)oxirene-2-carboxylic acid, 1a-ethyl-1a,2,4,9,11,11a-hexahydro-3,8,10-trihydroxy-4,9-dioxo-, methyl ester, (1aR-(1aalpha,2beta,11aalpha))-