Dimesityl ether

Malonic acid, amino-, diethyl ester, HYDROCHLORIDE, 40, 24 Malonic acid, bts(hydroxymethyl)-, DIETHYL ETHER, 40, 27 Malonitrile, condensation with tetra-cyanoethylene, 41, 99 2-Mercaptopyrimidine, 43, 6S hydrochloride of, 43, 68 Mercuric oxide in preparation of bromo-cyclopropane, 43, 9 Mesityl isocyanide, 41,103 5-Methallyl-l,2,3,4,5-pentachlorocyclo-pentadiene, 43, 92 Methane, dimesityl-, 43, 57 Methanesiileinyl chloride, 40, 62 Methanesulfonic acid, solvent for making peroxybenzoic acid from benzoic acid, 43, 93... 

The success of this transformation depends upon the oxidation potential of the ESE group (Eox 1.5 V), which is lower than that of the alkyl silyl ether group (Eax 2.5 V). Recently, Schmittel et al.35 showed (by product studies) that the enol derivatives of sterically hindered ketones (e.g., 2,2-dimesityl-1-phenyletha-none) can indeed be readily oxidized to the corresponding cation radicals, radicals and a-carbonyl cations either chemically with standard one-electron oxidants (such as tris(/>-bromophenyl)aminium hexachloroantimonate or ceric ammonium nitrate) or electrochemically (equation 10). 

These authors also noted that the electron-donor ability of various derivatives of 2,2-dimesityl-1-phenylethenol decreases in the order enolate > enol > enol silyl ether > enol phosphate > enol acetate. As such, a simple derivatization allows the ready modulation of the electron-donor properties of ends. 

Dimesityl-2,2-diphenylsilene (169) can be prepared by irradiation of the novel air-stable disilathietane (170). In contrast, the disilanylbenzoquinones (171) undergo photochemically induced conversion into the silyl ethers (172) in alcohols and into the silicon heterocycles (173) in the presence of ketones, in both transformations via the unstable sila-m-quinones (174). o-Silaquinone methides are intermediates in the photoreactions of... 

A similar reactivity order was found recently for competition between intramolecular cyclization and intermolecular capture. The AgBF4-assisted solvolysis of trimesityl vinyl chloride 21 in alcohols gives both the ether 23 and 2,3-dimesityl-4,6-dimethylindene, 24 (equation 11 Mes = 2,4,6-Me3C6H2) (80). These compounds are derived from the trimesitylvinyl cation... 

Technically significant is the finding that 4 can be generated in situ from 1 and l,3-dimesityl-4,5-dihydroimidazolium tetrafluoroborate (treatment of the salt with t-BuOK in THF at room temperature for < 1 min). The RCM is performed in the presence of ethereal HCl. ... 

Lithiation of hexamethylphosphoric triamide with MeLi in ether followed by addition of dimesityl- or mesitylphenylketene yields the stable enols (181 Ar = Ph or mesityl) together with the amides MesCHArCONMeR (R = Me or Et). The structures of... 

---