Reaction Steps
4-Methylbenzenesulfonyl chloride (5.70 g, 30 mmol), 3-octyn-1-ol (1.52 mL, 20 mmol) and pyridine (3.24 mL, 40 mmol) in CH2Cl2 (20 mL) were treated according to Procedure 4 giving oct-3-ynyl 4-methylbenzenesulfonate (5.21 g, 93%) as a colourless oil. Vanillin (0.90 g, 5.94 mmol) was alkylated with oct-3-ynyl 4-methylbenzenesulfonate (2.50 g, 8.92 mmol) according to Procedure 4 and the crude product was recrystallised from purified by flash chromatography with 10% EtOAc/petrol as eluent to give 3-methoxy-4-(oct-3-ynyloxy)benzaldehyde (0.25 g, 16%) as a colourless crystalline solid; mp 64.5-65.5° C.; δH (400 MHz, CDCl3) 0.86 (t, J=7.2 Hz, 3H, CH3), 1.32-1.44 (m, 4H, CH3CH2CH2), 2.12 (t, J=7.2 Hz, 2H, CH2), 2.69 (t, J=7.2 Hz, 2H, CH2CH2O), 3.88 (s, 3H, OCH3), 4.15 (t, J=7.2 Hz, 2H, OCH2), 6.96 (d, J5,6=8.0 Hz, 1H, H5), 7.37 (s, 1H, H2), 7.39 (d, J5,6=8.0 Hz, 1H, H6), 9.80 (s, 1H, CHO); δC (100 MHz, CDCl3) 13.5, 18.3, 19.5, 21.8, 30.8, 55.9, 67.5, 74.8, 82.5, 109.4, 111.7, 126.4, 130.2, 149.7, 153.4, 190.7; vmax 1020, 1132, 1262, 1508, 1584, 1684, 2931 cm−1.
