Synthesis of Aryl Tetralone Derivatives by Chalcone Route

Podophyllotoxin is a potent antimitotic agent. Podophyllin is a resinous extract of medicinal plants Podophyllum emodi and Podophyllum peltatum belonging to the family Berbideraceae in which the podophyllotoxin is one of the main constituent. The toxicity of podophyllotoxin liberates as diarrhea, nausea, vomiting. Hence modifications in podophyllotoxin structure are required to reduce its toxicity and to enhance its biological activity. The biologically active and lesscytotoxic new tetralone intermediates of podophyllotoxin have been synthesized. The modification of podophyllotoxin structure might enhance the biological activity with favorable solubility and reduced toxicity. Some synthesized analogues of podophyllotoxin showed better antibacterial activity. The structures of the synthesized new tetralone compounds were confirmed by IR, 1H-NMR, 13C-NMR and Mass spectral data. They will be screened for biological activities.

It was planned to synthesize analogues of podophyllotoxin by modifying lactone ring-A with some linked to ring A is replaced by dimethoxy, methoxy, methyl, H. Chalcones 3a-d were prepared by Claisen-Schmidt reaction of acetophenone 1a-dwith 3, 4, 5-trimethoxybenzaldehyde separately in the presence of potassiumhydroxide in water-ethanol mixture. Cyclopropyl ketones 4a-d was prepared in good yields by the reaction of chalcones 2a-d with diiodomethane in presence of Zn-Cu couple.