Oh, God! I thought there probably was no A between M and C. I just didn't feel like doing a search at the time. Though I should have.And as for MacDonalds, it is actually McDonald's, there is no A.
There is a Schwa between the M and C however, and since the A in the Russian МакДоналдс is unstressed, it is pretty much a Schwa anyway.
It's strange that Americans tend to pronounce the word 'Jack' incorrectly in Russian, although in Russian it sounds the same way as in English.