Oxidation of Secondary Methyl Ethers to Ketones

Abstract

We present a mild way of converting secondary methyl ethers into ketones using calcium hypochlorite in aqueous acetonitrile with acetic acid as activator. The reaction is compatible with various oxygen- and nitrogen-containing functional groups and afforded the corresponding ketones in up to 98% yield. The use of this methodology could expand the application of the methyl group as a useful protecting group.

Tuning Regioselectivity of Wacker Oxidation in One Catalytic System: Small Change Makes Big Step

“…2-(4-Oxopentyl) isoindoline-1,3-dione (2j). 17 This compound was prepared according to the general procedure, purified by flash column chromatography (PE/EA = 10/1), as white solid (89 mg, 81%. 1 H NMR (400 MHz, CDCl 3 ) δ 7.86−7.81 (m, 2 H), 7.73−7.69 (m, 2 H), 3.70 (t, J = 6.6 Hz, 2 H), 2.49 (t, J = 7.2 Hz, 2 H), 2.13 (s, 3 H), 1.94−1.91 (m, 2 H).…”

Access to Wieland–Miescher Diketone-Derived Building Blocks by Stereoselective Construction of the C-9 Quaternary Carbon Center Using the Mukaiyama Aldol Reaction

“…The C-11 stereochemistry of the major diastereomer ( syn relationship between C-11 and C-9) is in accordance with the Noyori stereoselectivity model . If benzyl ether deprotection of adducts 16a – e leading to the corresponding synthetically useful alcohols could be envisioned by hydrogenation over Pd/C or use of DDQ, chemoselective cleavage of methyl ethers 12a – p might be an issue, even though demethylation methodologies have been developed . To circumvent such problems, we decided to apply our reaction conditions (Table ) to silylated mixed acetals.…”

“…Even though the direct use of aldehydes was not possible, the corresponding dimethyl, dibenzyl, or alkyl/silyl-mixed acetals reacted on silyl enol ether 8 in the presence of SnCl 4 with relatively good yields, which proved to be a novel alternative pathway to prepare useful terpenoid precursors. The corresponding aldols might be obtained by selective cleavage of methyl ethers, benzyl ether, or silyl ethers leading to synthetically useful intermediates. Moreover, this method is highly diastereoselective and has been proven robust by an easy scale-up to afford adducts 12g , 12h , and 16e as enantiomeric precursors for the total syntheses of (+)-aureol and (+)-strongylin A, which are currently under investigation from ent -3 in our laboratory and will be published in due course.…”

One-Step Direct Oxidation of Alkoxy to Ketone for Evaporable Fullerene-Fused Ketone as Efficient Electron-Transport Materials

“…1 However, the oxidation methods are limited when alcohols are protected/functionalized with an alkyl group to form the alkoxy structure, 2 which is mainly attributed to high activation energy barrier for directly converting the alkoxy group to ketone structure. 3 Consequently, the one-step direct oxidation of alkoxy to ketone has yet to be presented.…”