Dehydrobromination of 3-bromo-3-cyclopentylhexane and number of possible alkene products I faced a question like this:


  The total number of alkene products possible from the dehydrobromination of 3-bromo-3-cyclopentylhexane is:


The answer is given 5. But I only found 3.


3-cyclopentylhex-2-ene
3-cyclopentylhex-3-ene
(hexan-3-ylidene)cyclopentane


I can't find the other 2. Any hint?
The structures (i) and (ii) have two isomers each,namely E and Z isomers.

For the structure (iii) there is a plane of symmetry (marked in the diagram) so it is not a geometrical isomer.

Thus Number of isomers=2 (of structure i) +2 (of structure        ii) + 1(of structure iii)= 5 isomers