Why didn't Adom eat from the tree of life first and then eat from the tree of knowledge so he can live forever?
Do any Medroshim discuss this?
The Ramban does not discuss this directly, but he does say the following:
Ramban Bereishis 2:9 - The Tree of Life gives long life, not eternal life.
Ramban Bereishis 2:17 - Before Adam ate from the Tree of Knowledge he would have lived forever.
Therefore, he would have gained nothing from eating of the Tree of Life before the Tree of Knowledge, as he was going to live indefinitely before eating from the Tree of Knowledge anyways. It is only after he ate from the Tree of Knowledge that his eating from the Tree of Life is a concern to Hashem.