First step: Not only can the cinnamaldehyde be oxidized by that reagent to cinnamic acid, but the formed epoxyaldehyde can also be oxidized, giving epoxy-cinnamic acid. I believe your proposed reaction is capable of producing a really big mess.
Second step: There is no literature precedence of any (substituted or not) epoxycinnamaldehyde being reduced to anything with a methyl group on the end, neither with the epoxide intact nor with it opened to the glycol.
As I have told other newbees a thousand times over - do not post a lot of "theoretically possible" routes to interesting chemicals without backing it up with literature references where others have performed a very similar procedure to prove the reaction to be practically feasible. Anyone with a little chemistry knowledge can draw up hundreds of diagrams like the one you just made, some of which may work and some of which fail - they are however useless to anyone unless the general concept is proven in practice.
Thus, please do not post anything like the above, unless you for example have a reference where someone successfully has reduced an epoxy-aldehyde to the corresponding propanediol in good yield, as a proof of concept...
