Synthesis of α,β-Unsaturated Ketones from Natural Triterpenoids and Sterol by IBX Mediated Oxidation
α,β-Unsaturated ketones have attracted much attention as some compounds showed remarkable bioactivities [1, 2, 3]. However, not many of these compounds exist in nature, whereas structures containing hydroxyl groups are abundant ; they provide an interesting entry point for chemical transformation to α,β-unsaturated ketones. The aim of this work is to study o-iodoxybenzoic acid (IBX) mediated oxidation, an efficient and user-friendly procedure for the oxidation of alcohols to α,β-unsaturated ketones [5, 6]. Two natural triterpenoids 20(R)-panaxatriol and taraxerol, previously isolated from Panax notoginseng and Pterospermum yunnanense , and one sterol β-sitosterol, were used as substrates. The reaction results in the formation of α,β-unsaturated ketones from the natural products used.
To a solution of the substrate (0.1–1.2 mmol) in DMSO–toluene (4:1, 5 mL) was added IBX (0.3–3.0 mmol) in one portion. The mixture was heated to 85°C, followed by TLC until no starting material was...
The work was supported by the Key Laboratory (No. 2016-5) and Science and Technology Innovation Team of Higher Education (No. 2014-6) in Yunnan, China.
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