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Hydrates ketones

Oxo Ion Salts. Salts of 0x0 ions, eg, nitrate, sulfate, perchlorate, hydroxide, iodate, phosphate, and oxalate, are readily obtained from aqueous solution. Thorium nitrate is readily formed by dissolution of thorium hydroxide in nitric acid from which, depending on the pH of solution, crystalline Th(N02)4 5H20 [33088-17 ] or Th(N02)4 4H20 [33088-16-3] can be obtained (23). Thorium nitrate is very soluble in water and in a host of oxygen-containing organic solvents, including alcohols, ethers, esters, and ketones. Hydrated thorium sulfate, Th(S0 2 H20, where n = 9, 8, 6, or 4, is... [Pg.37]

A solution of the 3-ketone hydrate (0.15 g) in acetone- -heptane is heated to boiling. After the acetone has been boiled off, a trace of concentrated hydrochloric acid is added to the -heptane solution and boiled for an additional 2 min. After cooling, the resulting crystals are collected by filtration, washed with dry -heptane and dried in vacuo overnight. Recrystallization from dry -heptane gives 17 -hydroxy-4,4-difluoroestr-5-en-3-one 0.98 g mp 123.5-124.5° [a] 134° (CHCI3). [Pg.488]

In contrast, the acid-catalyzed hydration of arylbenzoylacetylenes differs markedly from the hydration of a-unsaturated ketones. Hydration of unsaturated ketones has been shown to proceed via a 1,4-addition mechanism where protonation occurs on oxygen to give an oxonium salt, followed by attack of water at the 0-carbon to give a hydroxy enol. The rate-limiting step has been shown to be the protonation of the hydroxy enol (27) ... [Pg.213]

Ketones from Aoetylenes Alkylation of carbonyl compounds (p T 108) with propargyi halides gives 7,5-acetyienic ketones. Hydration then gives a 1,4-diketone of a type we shall use in Chapter T 25 as in the following example, ... [Pg.176]

The use of mesitoic acid esters has again been successfully employed by Burrows and Topping (1975) in the elucidation of intramolecular carbon acid participation. Under basic aqueous conditions, 2-acetylphenyl mesitoate [41] hydrolyses to yield mesitoic acid and 2-hydroxyacetophenone, reacting with intramolecular catalysis via the monoanion of the ketonic hydrate (see p. 192). However, in 47.5% aqueous ethanol containing potassium hydroxide, the reaction products from l-acetyl-2-naphthyl mesitoate [45] were found... [Pg.197]

Phosphinic acid Sulfonamide Sulfone Ketone hydrate... [Pg.262]

C-3 as determined by mass spectral analysis.(55) In a mechanism involving ketone hydration prior to bindTrTg, incorporation in recovered inhibitor should be at least 50%, a value corresponding to that expected for a single cycle of nonstereospecific addition/nonstereospecific elimination of water to the ketone carbonyl. The actual results then indicate that addition-elimination is a highly stereospecific process and thus enzyme-catalyzed. [Pg.233]

STATINE ANALOGUE DIFLUORO KETONE HYDRATE HYDROXYETHYLAMINE... [Pg.127]

Both acid and metal catalysis are usually required to accomplish hydration of alkynes to yield carbonyl compounds.34 The addition is usually regioselective, allowing for conversion of terminal alkynes to ketones. Hydration of acetylene to produce acetaldehyde used to be an industrially significant process but was replaced by the Wacker synthesis. [Pg.287]

In a similar way, perfluoro bieyelie ketone hydrate 15 rearranges under flash-vacuum pyrolysis to perfluorocyclohexa-2,4-dien-l-one (16).16... [Pg.255]

A very reactive ketone, obtained by Swern oxidation, is condensed in one-pot with MeMgBr. Other oxidation methods lead to the isolation of the ketone hydrate, which fails to react efficiently with Grignard reagents. [Pg.160]

H20 or alcohols as nucleophiles give low molecular weight compounds when they add to the C=0 double bond of carbonyl compounds. These addition products are called aldehyde or ketone hydrates (Section 9.1.1) and hemiacetals or hemiketals (Section 9.1.2), respectively, depending on whether they result from the addition to an aldehyde or a ketone. Today, one no longer distinguishes systematically between hemiacetals and hemiketals, but the expression hemiacetal is frequently used to cover both. [Pg.359]

A further complication arises if the ketone hydrate is also present in solution. Measured rate coefficients for proton transfer involving ketones may also require correction for these effects [83]. [Pg.126]

This method finds commercial application in the production of acetaldehyde from acetylene. Mercuric salts in the presence of dilute sulfuric acid act as the catalyst. The reaction has been extended to higher alkylacetylenes, which are obtained in about 60% yield from sodium acetylide and alkyl halides. These compounds are readily hydrated in aqueous solutions of acetone, methanol, or acetic acid to give 80-90% yields of the corresponding methyl ketones, fot example, methyl butyl, methyl amyl, and methyl hexyl ketones. Hydration has been accomplished by passing the acetylenic hydrocarbon and steam over a phosphoric acid catalyst at 150-204° and atmospheric pressure. ... [Pg.175]

Cyclohexanone and some alkyl derivatives can ring contract to the corresponding cyclopentanecarboxyhc acid the reaction is promoted by thallium(lll). Alternative mechanisms which have been proposed by (i) Wiberg and Koch and (ii) McKillop et a/. involve a 2-thaUyl ketone hydrate which either (i) loses TU and a proton in ring contraction or (ii) loses T1+ first, giving rise to a protonated hydroxyoxirane... [Pg.28]

In the experimental sequence, the authors at this point replace methylene chloride by THF (tetrahydrofuran) and the mixture is exposed to a mild ba.se in a two-phase system. The three carbonyl groups of V should all be reactive towards nucleophilic bases such as hydroxide ion, but they also differ remarkably in their susceptibility. Of the three, the keto function would be expected to be more prone to react as a consequence of dipole-dipole interactions with its vicinal ester grouping. The intermediate ketone hydrate anion VI may in principle trigger the disconnection of the three bonds around the central carbon as follows ... [Pg.193]

The pathway from the equilibrium mixture XV-XVI to the target compound II may well split again to follow a ketonic-type cleavage either via nitrile ketone hydrate (XX - XXI), or by a shorter route that requires the intervention of XXVII (see Scheme 16.4). [Pg.220]

The carbanions derived from acylthiophenes have been condensed with aldehydes, -" and, through the Claisen condensation with esters, thienylsubstituted j8-diketones have been obtained. 2-Thenoyl trifluoroacetone, first prepared by Reid and Calvin through the Claisen condensation of 2-acetylthiophene with ethyl trifluoracetate, has become an extremely useful chelating agent for the extraction of numerous elements from strongly acidic solutions. The tautomeric form which dominates in aqueous solution is the ketone hydrate. Other thiophenes have also proved useful for analytical purposes. - ... [Pg.55]

The mercuric ion-catalyzed hydration of alkynes probably proceeds in a similar manner to the oxymercuration of alkenes (see Section 5.1). Electrophilic addition of Hg to the triple bond leads to a vinylic cation, which is trapped by water to give an vinylic organomercury intermediate. Unlike the alkene oxymercuration, which requires reductive removal of the mercury by NaBH4, the vinylic mercury intermediate is cleaved under the acidic reaction conditions to give the enol, which tautomerizes to the ketone. Hydration of terminal alkynes follows the Mai kovnikov rule to furnish methyl ketones. ° ... [Pg.201]

Saxitoxin, the paralytic shellfish poison, has finally revealed its structure as (87) by X-ray crystallographic analysis of its ethyl hemiketal " and p-bromobenzene-sulphonate derivatives. C n.m.r. studies show that saxitoxin exists primarily as its ketone hydrate in aqueous solution. ... [Pg.313]


See other pages where Hydrates ketones is mentioned: [Pg.1305]    [Pg.296]    [Pg.185]    [Pg.248]    [Pg.124]    [Pg.111]    [Pg.719]    [Pg.236]    [Pg.28]    [Pg.28]    [Pg.58]    [Pg.30]    [Pg.313]    [Pg.314]    [Pg.772]    [Pg.266]    [Pg.124]    [Pg.126]    [Pg.83]    [Pg.83]    [Pg.1911]    [Pg.202]    [Pg.228]    [Pg.229]   
See also in sourсe #XX -- [ Pg.705 ]

See also in sourсe #XX -- [ Pg.705 ]

See also in sourсe #XX -- [ Pg.572 , Pg.573 ]

See also in sourсe #XX -- [ Pg.731 ]




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1.1- Diols ketone hydrates

Equilibrium constants for hydration of aldehydes and ketones

From ketones Hydration

Hydrate from ketones

Hydrates from water + ketones

Hydrates, of aldehydes and ketones

Hydration ketone synthesis

Hydration of Alkynes to Aldehydes and Ketones

Hydration of aldehydes and ketones

Hydration of an Aldehyde or Ketone in Acid Solution

Hydration of an Aldehyde or Ketone in Basic Solution

Hydration of ketones

Ketone hydrates ketones

Ketone mechanism of hydration

Ketones alkyne hydration

Ketones by hydration of alkynes

Ketones from acid-catalyzed hydration reactions

Ketones from alkynes hydration

Ketones from hydration of alkynes

Ketones hydrated forms

Ketones hydration

Ketones hydration

Ketones hydration of alkynes

Potential energy hydration of aldehydes and ketones

Steric effects in hydration of aldehydes and ketones

Unsaturated ketones base-catalyzed hydration

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