Figure 6. Intrinsic reaction coordinate (IRC) curve of TS2 and
energy level diagram of elementary reaction 2.
Elementary reaction 3.
The intramolecular reaction of intermediate med1, which was formed by
elementary reaction 2, can occur through the following two pathways.
Path 1: The electron-rich O atom of the nitroso group attacks the C atom
on the Carbonyl directly, and intermediate med1 is cyclized through the
five-membered transition state, TS3’, to form intermediate med1-1. The
electron-rich O(14) atom of med1-1 is then protonated in solution to
form product 3a , as shown in Figure 7.