When acetone is treated with anhydrous ammonia in the presence of anhydrous calcium chloride (a common drying agent), crystalline product C is obtained on concentration of the organic liquid phase of the reaction mixture.
These are spectral data for product C:
MS (m/z): 155 (M+.), 140
IR (cm-1): 3350 (sharp), 2850-2960, 1705
1H NMR (δ): 2.3 (s, 4H), 1.7 (1H; disappears in D2O), and 1.2 (s, 12H)
(a) What is the structure of C?
(b) Propose a mechanism for the formation of C.