(3a-alpha,4-beta,7-beta,7a-alpha)-Hexahydro-4,7-epoxybenzo(c)thiophene-1,3-dione 109282-38-4 4,7-Epoxybenzo(c)thiophene-1,3-dione, hexahydro-, (3a-alpha,4-beta,7-beta,7a-alpha)- Endothall thioanhydride