Is It Best to Jump Start a 99 740il from Under the Hood or Directly from the Battery in the Trunk?

My car is dead and I tried to jump start from the connections under the hood but Nothing?

Suggestion:

come off the battery. Not sure where you are trying to connect under the hood, but there is a direct 4 gauge wire from the battery to the starter. Doubt you are connected to it.
Now, if you get no reaction from a connection to the battery, you have more trouble.