too stepwise, a convergent synthesis would be far better.
it is most likely unnecessary to form that pyridine ring, there must be a way to install that ring in one piece (maybe grignard to an aldehyde or some sort of metal catalysed reaction
I wouldn't use mercury if you can avoid, an acetal would be far better. doing a Jones oxidation at such a late stage of a long synthesis is a bad idea as your molecule may not tolerate the acid. there are many better conditions.
i dont have time to go over this in detail but you should first consider these points.