As WhiteRav3n points out, one goal of alchemy has now been realized - it's possible to turn lead into gold. (Though she is incorrect in one particular - it was lead, not iron, that was considered the basest of metals.) All you need to do to turn one substance into another is add protons, and enough neutrons and electrons to stabilize it.
But that's not how alchemists tried to do it; they were on the wrong track, as it turned out. Alchemy is still a viable philosophical system, but modern nuclear chemistry is what has finally let us transmute elements. However, there are other goals to alchemy, like the purification of substances, which may be of interest to you; I would search online for more information.
Now, the other ultimate goal of alchemy - immortality - still eludes us... but there's no reason to believe it's impossible. We age and die for several reasons, like the elimination of telomeres in chromosomes; there are many scientific techniques in the works to stop this from happening. Perhaps one day in the future, the philosopher's stone will be created by science.