(3R,4S,5S,6R)-1,3,4,5,6-pentachlorocyclohexene 319-94-8 C06596 gamma-Pentachlorocyclohexene 1,3(R),4(S),5(S),6(R)-Pentachlorocyclohexene 1,3,4,5,6-pentachlorocyclohexene c0514