1. He hadn't been gone two minutes when there was an explosion.(original) 2. He hadn't been and gone two minutes when there was an explosion. BEEN AND GONE doesn't really make sense, or implies that he left and came back, which is not the original meaning. 3. He hadn't been gone for two minutes when there was an explosion. OK - basically the same as 1. 4. After he left there for two minutes there was an explosion there. NOT GOOD The sentence seems to mply that the act of leaving took two minutes, which is incorrect. 5. He did not leave there for two minutes until there was an explosion. GRAMMATICALLY OK, i think it need a comma after 'minutes'. But does not mean the same as the original, i.e. it's saying he left at the same time as the explosion. 6. He did not leave until there was an explosion for two minutes. GRAMMATICALLY ALMOST OK, but different meaning. It's saying that the explosion lasted two minutes, after which he left. 7. Just as he left there for two minutes then suddenly an explosion happened. NOT GOOD, for the same reason as 4.

2-7 are (very) wrong. Similar to (and more conventional than) the original: Two minutes after he left there was an explosion. There was an explosion two minutes after he left. Unless there is a connection between him being gone and the explosion, there’s no need for this structure. An example of there being a connection: I hadn’t been working for 30 minutes, so my boss got mad at me. (My activity in the past created another event in the past)

I think sentence 1 is the best. I would write it as either, A. “Two minutes after he left the explosion occurred. “ or B. “He hadn’t been gone but two minutes when an explosion occurred.”

Number 2 sort of means the same as number 1. Number one is the correct way to say it. Numbers 3-7 are all different. They don’t really make sense, and so far as they do they are hard to understand.