Short answer:
Not likely. He managed to recreate a technology without blueprints, schematics, or a clean room, made completely of spare parts and miniaturized a technology to one ten thousandths, of it actual size AND make it produce the energy output of a small nuclear reactor. Oh yes, did I mention he did it in under a week? See: Phlebotinum
Longer Answer
You cannot take this stuff seriously. This is one of those comic things where a willing suspension of belief is an absolute requirement.
It is completely impossible for him to have created his personal arc reactor under those conditions. The idea of Tony Stark, as a character, is that he is genius personified. In the Marvel Universe, he is one of the most inventive, creative and adaptive humans alive.
The arc reactor had existed for at least 30 years, as Obidiah Stane reminds Tony, as a publicity stunt, nothing more. It was not energy effective, implying it cost as much in energy to run it as it produced.

- You must also remember, this story is an adaptation of the original Iron Man story where he did not create the Arc Reactor, he just created the basic Iron Man Armor. That armor ran on batteries. In its heyday, it would have been considered a fantastic device (being honest, even today, the first comic version of the Iron Man prototype would be a game changer.)

The very first Iron Man armor. Grey, dull, and ran on battery power. It's initial power? It deflected bullets.
And such as it is when something is adapted for movies, the adaptation always tries to exceed the original. Given its immense size, power requirements and up to this point inability to be a break-even proposition on energy, it would have been nothing more than a pretty science project in Stark's book.
So in this one, Tony will, somehow, create an energy source, faster, stronger, better, cleaner and ten thousand times smaller, than anything ever seen before from the stone knives and bearskins lying around a terrorists camp in some Third World Nation (filled with his weapons) and in addition to the miracle of the Iron Man Armor, he will also create the world's first pocket-sized tokamak fusion reactor.

This is a real tokomak fusion reactor. It is an immense thing, far larger than even the arc reactor (show above)
- You are not supposed to take it seriously and wonder why he never created this before, you are supposed to be in awe of him creating it under such adverse conditions, while shrapnel is approaching his heart, while terrorists are terrorizing him, and he doesn't even have access to a clean room.