“…1 H-NMR (300 MHz, CDCl 3 ) δ: 5.41 (brs, 1H), 3.17−3.24 (td, J = 7.1, 6.3 Hz, 2H), 1.95 (s, 3H), 1.41−1.49 (br, 2H), 1.28 (br, 10H), 0.86 (t, J = 6.7, 5.9 Hz, 3H). 13 (20), 142 (17), 128 (17), 114 (35), 101 (14), 100 (48), 87 (21), 79 (98), 72 (100), 60 (34), 55 (13), 44 (22), 43 (37), 41 (10) Synthesis of 13b. To a solution of 4 (174 mg, 1.00 mmol) in CH 3 CN (1 mL) in a round flask (10 mL) equipped with a stirring bar was added allylamine (150 μL, 2.00 mmol) in one shot, and the mixture was stirred for 25 h under an Ar atmosphere at 30 °C.…”