Chemistry - GOC Question with Solution | TestHub
For each problem below, draw the intermediate that you get after pushing the arrows. The total number of atoms bearing a formal negative charge in the intermediates drawn for (a) to (d) is :
(a) 
(b) 
(c) 
(d) 
Options:
Answer:
Solution:
(a) The C-I bond breaks, with the leaving group being I-, resulting in a tertiary carbocation and an iodide ion.
(b) NH3 adds to the carbonyl carbon, and the π electron pair moves onto the oxygen atom, forming a tetrahedral intermediate with an O- and an NH3+ group.
(c) The π bond attacks the hydrogen of HBr. The H-Br bond breaks, with Br- leaving, resulting in a tertiary carbocation and a bromide ion.
(d) Water opens the protonated epoxide ring as the C-O bond breaks, with the electron pair moving onto the oxygen atom, forming protonated ethane-1,2-diol. The negatively charged atoms are I-, O-, and Br-, totaling 3. Therefore, the answer is (A).
