Oxygen-stabilized

The negative charge is shared equally by all three oxygens Stabilization of nitrate ion by electron delocalization increases the equilibrium constant for its formation... 

Oxygen stabilized carbocations of this type are far more stable than tertiary carbocations They are best represented by structures m which the positive charge is on oxygen because all the atoms have octets of electrons m such a structure Their stability permits them to be formed rapidly resulting m rates of electrophilic aromatic substitution that are much faster than that of benzene... 

Mass Spectrometry Ethers like alcohols lose an alkyl radical from their molecular ion to give an oxygen stabilized cation Thus m/z 73 and m/z 87 are both more abun dant than the molecular ion m the mass spectrum of sec butyl ethyl ether... 

There is another oxygen stabilized cation of m/z 87 capable of... 

Group II — Ramovol of Oxygen (Stability A Combustion Improvement]... 

There is another oxygen-stabilized cation of mIz 87 capable of being formed by fragmentation of the molecular ion in the mass spectrum of sec-butyl ethyl ether. Suggest a reasonable structure for this ion. 

When this sequence is applied to carbohydrates, the first step takes place intramoleai-larly to yield a cyclic hemiacetal. The second step is intermolecular, requires an alcohol R"OH as a reactant, and proceeds readily only in the presence of an acid catalyst. An oxygen-stabilized carbocation is an intermediate. 

Trihydroxycyclopropenium ion and homologous ions Hogeveen dication [C6(CH3)6] 256 11 Oxygen-stabilized carbodications 257 References 258... 

The reaction of 1-isopropoxy-l-trimethylsiloxycyclopropane (1, R = i-Pr) with TiCl yields the titanium homoenolate of isopropyl propionate 2 (R = i-Pr) and Me3SiCl (Eq. see 9). That of 23, in contrast, yields a considerable fraction of the homoenolate of silyl propionate as well, Eq. (66) [19]. Apparently, the loss of an isopropyl group from an oxygen-stabilized cationic intermediate competes with that of the silyl group with bulky substituents. 

In a 2- (5-) substituted tetrahydrofuran loss of the 2-substituent is nearly always important because it leaves behind an oxygen-stabilized cation. Scheme 14 displays the fissions that allow a ready identification of the position of the tetrahydrofuran residue in a long chain but not the stereochemistry, the cis and trans isomers having nearly identical spectra (72MI31000). The series designated in that scheme was produced by the oxygenation of lipids... 

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