“…The organic layer was dried over Na 2 SO 4 , and the solvent was evaporated in vacuo. The residue was purified by silica gel column chromatography using the solvents given in Table 1 [47,48]. Compounds 6,7,8,13,14,17,18,20,21,22,23,24,25,26,27,28,29,30,31 and 32 were prepared according to the method I. were added to a solution of caffeic acid (or ferulic acid) (0.91 mmol) in dry CH 2 Cl 2 (15 ml) at 0 C and the mixture was stirred at room temperature for 15 min under N 2 .…”