tailieunhanh - Selective and efficient oxidation of unsaturated alcohols as constituents in essential oils

Essential oil unsaturated alcohols have been oxidized efficiently into the corresponding unsaturated aldehydes by potassium permanganate supported copper(II) sulfate pentahydrate. Unsaturated aldehydes such as geranial and cinnamaldehyde being valuable components in food, cosmetic, perfumery and pharmaceutical chemistry, have been obtained in good yields (> 60%) under two activation methods: microwave irradiation and conventional heating. | Journal of Science and Technology 54 (2C) (2016) 320-327 SELECTIVE AND EFFICIENT OXIDATION OF UNSATURATED ALCOHOLS AS CONSTITUENTS IN ESSENTIAL OILS Luu Thi Xuan Thi Department of Organic Chemistry, Faculty of Chemistry, University of Science - VNUHCM, 227 Nguyen Van Cu St., Dist. 5, Ho Chi Minh City, Vietnam Email: ltxthi@ Received: 31 May 2016; Accepted for publication: 23 October 2016 ABSTRACT Essential oil unsaturated alcohols have been oxidized efficiently into the corresponding unsaturated aldehydes by potassium permanganate supported copper(II) sulfate pentahydrate. Unsaturated aldehydes such as geranial and cinnamaldehyde being valuable components in food, cosmetic, perfumery and pharmaceutical chemistry, have been obtained in good yields (> 60%) under two activation methods: microwave irradiation and conventional heating. Keywords: potassium permanganate, copper(II) sulfate, microwave irradiation, unsaturated alcohol. 1. INTRODUCTION The selective oxidation of alcohols into aldehydes or ketones is one of the most important transformations in organic syntheses [1], especially the oxidation of unsaturated alcohols into the corresponding unsaturated carbonyl compounds, . the conversion of geraniol or nerol into geranial or neral, and the conversion of cinnamyl alcohol into cinnamaldehyde. These generated unsaturated aldehydes are important intermediates for the production of perfumes, fragrances and pharmaceuticals [2, 3]. Various oxidants have been proposed for the oxidation of unsaturated alcohols, for instance lead tetraacetate [4], potassium permaganate in alkaline media or supported by bentonite/CuSO4 5H2O in the presence of solvent [5, 6], N-methylmorpholine N-oxide catalysed by RuCl3 in dimethylformamide [7], and tetrapropylammonium perruthenate (TPAP) were studied [8]. From both economics and environmental viewpoints, green oxidants have been paid attention and developed by using molecular oxygen catalyzed by sodium nitrite and .