Combined, evaporated re-dissolved in benzene, and freeze-dried to provide 12 (1.8376 g, 68.2 ) as
Combined, evaporated re-dissolved in benzene, and freeze-dried to give 12 (1.8376 g, 68.2 ) as a colorless oil that turned into a white waxy-solid. IR (CHCl3): 3300, 1738 br, 1710…