*(1E,6E)-4,4-Diethyl-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,6-diene-3,5-dione* (**3m**)

Yield: 87%; mp = 114–115 ◦C; 1H-NMR (CDCl3) δ 7.64 (d, *J* = 15.5 Hz, 2H), 7.05 (dd, *J* = 8.3, 1.5 Hz, 2H), 6.95 (d, *J* = 2.0 Hz, 2H), 6.85 (d, *J* = 8.0 Hz, 2H), 6.59 (d, *J* = 15.5 Hz, 2H), 5.88 (s, 2H), 3.88 (s, 6H), 2.06 (q, *J* = 7.5 Hz, 4H), 0.71 (t, *J* = 7.5 Hz, 6H); 13C-NMR (CDCl3) δ 197.9, 148.5, 146.7, 144.0, 126.8, 124.2, 119.6, 114.7, 109.7, 69.0, 56.1, 21.6, 7.7; HRMS [ESI]<sup>+</sup> calculated for C25H28NaO6: 447.1784 [M + Na]+; found: 447.1788.
