The 7th structure is also optically active. (1S,2R)-1-(Chloromethyl)-2-methylcyclopentane is different from (1R,2S)-1-(chloromethyl)-2-methylcyclopentane.
The 7th structure is also optically active. (1S,2R)-1-(Chloromethyl)-2-methylcyclopentane is different from (1R,2S)-1-(chloromethyl)-2-methylcyclopentane.