Reaction Steps
A suspension of dimethyl 2-methaxy-5-tert-butylbenzylphosphonate (11) (1.01 g, 3.53 mmol) and sodium hydride (60% in oil, 0.17 g, 4.25 mmol) in dry DMF (29 ml) was cooled with stirring co 6° C. under argon. A solution of 4-stilbenecarbaldehyde (12) (0.88 g, 4.23 mmol) in dry DMF (21 ml) was added dropwise with stirring keeping the reaction temperature at 5° C. and then the reaction mixture was stirred at room temperature for 3.75 h under argon. Water (100 ml) and ether (300 ml) were added. The organic layer was separated, washed with water (3×100 ml), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The residue was purified by column chromatography over silica (dichloromethane/hexane; 1:1) and recrystallised from dichloromethane/hexane/methanol to yield a pale yellow solid of (8) (0.95 g, 73%), m.p. 129°-129.5° C.; (Found: C, 88.06; H, 7.62. C27H28O requires C, 88.00; H, 7.66%); λmax /nm (CH2Cl2) 362 (log ε 4.72); 8H (CDCl3) 1.36 (9 H, s, tert-butyl), 3.88 (3 H, s, OCH3), 6.85 (1 H, d, JH4,H3 =8.6 Hz, H3), 7.13 (1 H, d, J=16.5 Hz, vinytic H), 7.125 (1 H, s, vinytic H), 7.26 H, m, H4"), 7.28 (1 H, dd, JH4 =8.6 Hz, JH6,H4 =2.44 Hz, H4), 7.37 (2 H, m, H3" and H5"), 7.53 (7 H, m, H2", H6", H2', H3', H5', H6', and vinylic H), 7.56 (2 H, m, H2' and H6') and 7.62 (1 H, d, JH4,H3 =2.4 Hz, H6); δC (CDCl3) 31.5 (CH3), 34.1 [C(CH3)3 ], 55.6 (OCH3), 110.5, 123.5,124.0, 125.6, 126.5, 126.7, 126.8, 127.5, 128.2, 128.4, 128.7, 136.3, 137.4, 137.5, 143.3 and 154.8; m/z 368.214.
