Fig. 24 in A comprehensive review: Biological activity, modification and synthetic methodologies of prenylated flavonoids

Fig. 24. Regioselective synthesis of C-6/C-8 prenylated flavonoids. Reagents and conditions: (a) TEA, TBDMS-Cl, H2SO4, dichloromethane, room temp., 83%; (b) Prenyl alcohol, TPP, DIAD, dichloromethane, ice bath, 56%; (c) Eu(fod), toluene, 140 ◦ C, 81%; (d) NaH, pivaloyl vanilloyl chloride (aq.), tetrahydrofuran, reflux, 3 85%; (e) CuCl, TMS-Cl, dry acetonitrile, RT, 60%; (f) i TBAF (aq.) dry tetrahydrofuran ii Pyrrolidine, H SO, 60%; (g) Pivaloyl chloride, DMAP, dry pyridine, 40 ◦ C, 2 2 4 15 min, H SO dilution; (h) TFA, dichloromethane, water, 30 ◦ C, 72%.