Crossing borders: On‐Water Synthesis of Flavanones

Abstract

In this article, a one‐pot methodology for the synthesis of flavanones “on‐water” from simple starting materials is reported. The reaction proceeds in basic media (KOH), at room‐temperature and in distilled water, during a period of 48 h with up to 96 % yields. In addition, most flavanones are obtained pure enough after a simple filtration procedure.

Total Synthesis and Antibacterial Evaluation of Lupinifolin and Its Natural Analogues

“…The mixture was stirred at 0 °C for 0.5 h and then reacted at room temperature for 2 h. After the reaction was completed (detected by TLC), the solvents were removed in vacuo. The residue obtained was purified over flash column chromatography with PE/EtOAc (50:1, v/v) as the eluent to give the corresponding ether (18a−c, 14,22).…”

“…Then base-catalyzed aldol condensation of 7 with benzaldehyde gave chalcone 8a in 95% yield after a simple purification . Optimization of the oxy-Michael reaction was performed with chalcone 8a using various bases. − After several attempts, sodium acetate (NaOAc) was chosen as the proper base to cyclize chalcone 8a to provide an equilibrium mixture of the cyclized product 9a (67%) and starting material 8a (15%). Then the −MOM protecting groups at C-4 and C-6 of 9a were removed by treatment with a diluted HCl solution to generate 10a (88%) .…”