1,2,4-Methenocyclopenta(cd)pentalene-5-carboxaldehyde, 2,2a,3,3,4,7-hexachlorodecahydro-, (1alpha,2beta,2abeta,4beta,4abeta,5beta,6abeta,6bbeta,7R*)- 7421-93-4 ENDRIN ALDEHYDE HSDB 6181 SD 7442