The sequence B-A#-A-A# is effectively what I started with. I rechecked my theory, and it seem to be correct. Somehow, playing it, it did not sound right to my ear (the other suggested run, with C instead of B, somehow sounds better). Also the suggested fingering in my edition (4-3-1-2, jumping then to 5 for the following G, seemed awkward at first. (Though after a few times it start seeming a lot more natural). From all that came my post.
I guess that my ear, among other things, needs improvement.
Thanks to all for the replies.