Question 8 (12 p) a) Complete the following reactions providing the structures of (A) and (B). b) Write a reasonable mechanism for the preparation of (B) from (A). (A) 2)H3O+1)CH3MgBr(2equivalents)/Et2O (B) HINT: (8) can also be obtained from phenylacetone (phenyl-2-propanone): 2)H3O+1)CH3MgBr/Et2O (B) Phenyl-2-propanone If you do not know the structure of (A) and thus you cannot answer part (b), write the mechanism for the preparation of (B) from phenylacetone (but you will get half points)