92688-77-2;4,7-Epoxybenzo[c]thiophene, 1,3,3a,4,7,7a-hexahydro-2,2-dioxide, (3a.alpha.,4.beta.,7.beta.,7a.alpha.)-;4,7-Epoxybenzo(c)thiophene, 1,3,3a,4,7,7a-hexahydro-2,2-dioxide, (3aalpha,4beta,7beta,7aalpha)-