Lord Voldemort is many times shown to be obsessed with the thought of never dying and many of his actions are based upon his fear of death. Rowling has stated this fear is pathological and that his Boggart would be his own corpse.
It is stated, in Harry Potter and the Philosopher's Stone, that Nicholas Flamel is the only known creator of the Philosopher's Stone. This suggests that creating a PS is not easily done, but that it could be.
Given these two, a few questions come to mind:
- Did Voldemort ever attempt to create a Philosopher's Stone?
- Did he ever attempt to seek out Nicholas Flamel, or his stone, prior to the first book?
- If no to the above questions, why didn't he?
I would prefer answers based in canon, but extrapolations and conclusions drawn from a variety of sources is of course more than welcome.