Stereoelectronic effects in carbamate carbonyl oxygen attack on halide 2-Bromoethyl (2-bromoethyl)carbamate can react through either Path A or Path B to form salt 1 or salt 2. In both instances the carbonyl oxygen functions as the
nucleophile in an intramolecular alkylation. What is the preferred reaction
path for the transformation in question?



I would go with A, but I don't know how to explain it.
Path A resembles a 5-enolexo-exo-tet reaction which is allowed by Baldwin rules while path B represents a 5-enolendo-exo-tet reaction which is disfavored. The orbital interactions of path B suffer severe geometrical constraints (even in the conformation where the C-Br bond is pointing towards the viewer when looking at the attached image). Path A is presented in the attached image.