How many Z-E Isomers are possible for the structure below?
Please see attached image.
It is asking for the number of isomers and gives the answer as “at each of the double bonds there can be two variants of the Z,E molecule. Thus, the total number is 2^4=16
At the carbon carbon double bond furthest to the right I can find the 4 Z,E isomers, as shown in the image.
But in the 2nd carbon carbon double bond from the right, I can only find 2 Z,E isomers, as shown in the image (because of the two Hs). Where do the last 2 Z,E isomers on the 2nd carbon carbon double bond from the right come from?