Ideas for the 2nd synthesis?
I was deliberately avoiding this one as I was at a bit of a loss because I had missed a vital difference between the starting material and the product and was barking up the wrong tree looking for some kind of rearrangement reaction, however...
For the second one you can start with ozonolysis.
..is quite clearly the way to go.
Start by sequentially numbering the carbon atoms in the starting material and then numbering the atoms in the product.
As you go through each step keep the numbering system of the starting material.
On the last step to get your product you will undoubtedly need to change your original numbering of the product, but I find this is a good technique to follow what it happening to each carbon throughout the synthesis.