- Preparation method of alpha, beta-epoxy ketone compound
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The invention provides a method for efficiently preparing an alpha, beta-epoxy ketone compound from alpha-hydrogen-containing alpha-halogenated ketone as a raw material and various aldehydes under theaction of DBU or DBN. Namely the method comprises the steps: slowly and dropwise adding a dichloromethane mixed solution of alpha-halogenated ketone and aldehydes into a dichloromethane solution of DBU or DBN under the conditions of inert gas shielding and 20 DEG C below zero, ending a reaction, and then, carrying out separation and purification to obtain the alpha, beta-epoxy ketone compound. The synthesis method provided by the invention is available in raw material, low in cost, simple and easily-controlled in operation, relatively few in side reactions, simple in aftertreatment, relatively high in product yield, capable of greatly reducing the production cost, relatively high in economic benefit and suitable for large-scale industrial production.
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Paragraph 0044-0047
(2019/07/29)
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- Synthesis of α,β-epoxy ketones from alkyl- and arylsubstituted cyclopropanols
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A number of aliphatic and arylaliphatic α,β-epoxy ketones were prepared in good yields in a one-pot procedure by a manganese-catalyzed ring cleavage of 1-substituted and 1,2-disubstituted cyclopropanols with oxygen followed by dehydration of the resulting
- Kulinkovich,Astashko,Tyvorskii,Ilyina
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p. 1453 - 1455
(2007/10/03)
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- A stereocontrolled approach to electrophilic epoxides
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Lithium t-butyl hydroperoxide (easily generated by addition of an alkyl-lithium to anhydrous t-butyl hydroperoxide in THF solution) is a powerful reagent for the epoxidation of electrophilic alkenes at -20 to 0 °C under full stereocontrol. Thus αβ-unsaturated esters, sulphones, sulphoximines, and amides are readily epoxidised with complete regio- and stereo-specificity and with considerable chiroselectivity (20-100%) when appropriate chiral auxiliaries such as menthyl, 8-phenylmenthyl, or a camphor-sulphonamide derivative are used. Asymmetric αβ-unsaturated sulphoximines undergo epoxidation with 100% diastereoselectivity. The only exceptions to stereocontrol noted are heavily substituted maleate esters such as di-t-butyl maleate. The αβ-epoxy amides are shown to be valuable sources of the corresponding epoxy ketones by treatment with an organolithium, allowing a stereo- and chemoselective entry in high yield to these useful intermediates.
- Meth-Cohn, Otto,Moore, Clive,Taljaard, Heinrich C.
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p. 2663 - 2674
(2007/10/02)
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