Are these three molecules optical isomers? In the structures below (2) vs (3) seem obvious optical isomers to me. 

But what about (1)? Is that just a stuctural isomer (e.g. Butane vs Isobutane) or is there a more specific way to describe the relation of (1) vs (2) / (3)?



Alternative sketch of (2) &amp; (3) based on the comment by @DGS below:
There is no exocyclic methylene in structure 1.  Is it not an optical isomer of 2 and 3.

Likely there is a pericyclic rearrangement between 1 and 2/3 which would formally render them tautomers.

2 and 3 are diastereomers.