Reaction Steps
Isovanillin (0.90 g, 5.9 mmol) was alkylated with oct-3-ynyl 4-methylbenzenesulfonate (2.5 g, 8.9 mmol) according to Procedure 2. The crude product was recrystallised from purified by flash chromatography with 10% EtOAc/petrol as eluent to give 4-methoxy-3-(oct-3-ynyloxy)benzaldehyde (0.52 g, 34%) as a colourless crystalline solid; mp 42-43° C.; δH (400 MHz, CDCl3) 0.90 (t, J=7.2 Hz, 3H, CH3), 1.37-1.49 (m, 4H, CH3CH2CH2), 2.16 (tt, J=7.2, 2.4 Hz, 2H, CH2), 2.72 (tt, J=7.2, 2.4 Hz, 2H, CH2CH2O), 3.95 (s, 3H, OCH3), 4.17 (t, J=7.2 Hz, 2H, OCH2), 6.98 (d, J5,6=8.0 Hz, 1H, H5), 7.44 (d, J2,6=2.0 Hz, 1H, H2), 7.47 (dd, J5,6=8.0, J2,6=2.0 Hz, 1H, H6), 9.85 (s, 1H, CHO); δC (100 MHz, CDCl3) 13.6, 18.4, 19.7, 21.9, 30.9, 56.2, 67.6, 75.1, 82.5, 110.8, 111.0, 126.9, 130.1, 148.6, 154.9, 190.8; vmax 1019, 1132, 1262, 1508, 1585, 1684, 2932 cm−1.
