Iron (III) chloride, Aluminium chloride and Zinc chloride as Catalysts in the Synthesis of Tetrahydropentagamavunon-0

Abstract

Tetrahydropentagamavunon-0 (THPGV-0), an analog of tetrahydrocurcumin, has chemical name as 2,5-bis(4'-hydroxy-3'-methoxybenzyl)-cyclopentanone. It can be synthesised from pentagamavunon-0 (PGV-0, 2,5-bis(4'-hydroxy-3'-methoxybenzylidene)-cyclopentanone). The hydrogenation reaction was applied in this synthesis and it was catalysed by palladium on carbon which yielded THPGV-0 in moderate yield. In seeking for a cheap catalyst, the different catalysts was applied in this hydrogenation reaction. The reaction condition was changed by using different catalysts other than palladium on carbon. Among  Palladium/carbon (Pd/C) 10 %, Iron (III) chloride (FeCl₃), Aluminium chloride (AlCl₃) dan Zinc chloride (ZnCl₂) only reaction catalysed by Pd/C gave THPGV-0. While others gave products like the side products when Pd/C used. Structure elucidation was carried out by using spectroscopic method. The obtained products from the reaction by using FeCl₃, and  AlCl₃ as catalysts are 1,3-bis(4'-hydroxy-3'-methoxybenzyl)cyclopentane and 2,5-bis(4'-hydroxy-3'-methoxybenzyl) cyclopentanol and by using ZnCl₂ as catalyst is 1,3-bis(4'-hydroxy-3'-methoxybenzyl)cyclopentane.

Keywords: Iron (III) chloride, Aluminium chloride, zinc chloride, tetrahydropentagamavunon-0