I don't think this is possible:
When you land at either of 2E's concourses, you are airside for immigration purposes, but landside for security purposes.
To enter either of 2E's shopping areas, you need to go through security. I would be surprised if they let you go through (they check and scan boarding passes). I know they will at least tell you it's the wrong terminal, I don't know if they would actually prevent you from going through (but I would be surprised if they didn't).
Depending on the exact combination of the concourse you land at and the concourse you may want to visit there may be some special cases where you could enter the departures area, but I highly doubt so.
Also remember that you will have to go through immigration, and this can be very, very, very long at times in CDG, especially if you have a non-EU passport and do not have status. Even the boss of Paris airports has publicly complained about it. You want to make sure this is sorted out as quickly as possible, and once you have done that, you definitely won't be able to enter the 2E departures area. You'll also have to go through security to reach 2F departures.
It's probably a better option to shop anywhere else in the EU (outside of airports, I mean) and claim a tax refund. There are related conditions (including minimum amounts), but it should be relatively straightforward.