3-(3,4,5-Trimethoxyphenyl)-propenal was prepared following the procedure for 3-(3-bromo-4,5-dimethoxyphenyl)-propenal as described in Example 15a using 3,4,5-trimethoxy benzaldehyde. 7-Methoxy-2-hydroxy-4-(3,4,5-trimethoxy-phenyl)-chroman was synthesized by the same procedure as Example 18 from 3-(3,4,5-trimethoxyphenyl)-propenal (71 mg; 0.32 mmol) and 3-methoxy phenol (43 mg; 0.35 mmol) using morpholine (30 μl) as a base in methanol (2.5 ml) (14 mg; 13%). 1H NMR (acetone-d6): 6.64 (dd, J=1.1, 8.5 Hz) and 6.59 (dd, J=1.0, 8.4 Hz) (1H), 6.54 (one doublet and one singlet overlapped, J=2.7 Hz; 2H), 6.38 (dd, J=2.6, 8.5 Hz; 1H), 6.34 (d overlapping with other small signals, J=2.3 Hz; 1H), 6.13 (d, J=6.8 Hz) and 6.08 (dd, J=1.0, 4.5 Hz) (1H), 5.62-5.65 and 5.47-5.51 (m each, 1H), 4.13-4.21 (overlapping dd, J=6.6, 10.2 Hz; 1H), 3.78, 3.77, 3.73, 3.72 (s each, 12H), 2.31 (ddd, J=2.1, 5.7, 13.1 Hz) and 2.08-2.13 (m) (2H).
