Ketones carbons

The 2-metalated thiazoles react with a variety of electrophilic substrates in a standard way, leading to addition products with aldehydes, ketones, carbon dioxide, epoxides, nitriles, Schiff bases, and to substitution products with alkyl iodides (12, 13, 437, 440). 

Poly(vinyl carbazole) is insoluble in alcohols, esters, ethers, ketones, carbon tetrachloride, aliphatic hydrocarbons and castor oil. It is swollen or dissolved by such agents as aromatic and chlorinated hydrocarbons and tetrahydrofuran. 

The carbonyl-group carbon atoms of aldehydes and ketones have characteristic 13C NMR resonances in the range 190 to 215 8. Since no other kinds of carbons absorb in this range, the presence of an NMR absorption near 200 8 is clear evidence for a carbonyl group. Saturated aldehyde or ketone carbons usually absorb in the region from 200 to 215 8, while aromatic and a,p-unsaturated carbonyl carbons absorb in the 190 to 200 5 region. 

The opportunity of employing various electrophiles and functionalized diene precursors greatly enhances the synthetic potential of p3-allyltitanocenes. Besides aldehydes and ketones, carbon dioxide [11,15,16], acid chlorides [17], imines [11], nitriles [11], isocyanides [11], and organotin halides [18] react to afford the corresponding allylated products after hydrolysis. Examples are given in Scheme 13.8. 

A similar substituted furan synthesis was realized via a Pd-catalyzed tandem carbonylation-arylation using an a,p-acetylenic ketone, carbon monoxide, and bromothiophene [104],... 

In all these reactions, crystallographic studies demonstrated the crystal control responsible for formation of the observed products. Thus, the prereaction ketone oxygen-steroidal hydrogen distance is in all cases 3.4 0.5 A, the ketonic carbon-steroidal (to-be-attacked) carbon distance is of the order of 4 A, and the... 

An interesting deoxygenation of ketones takes place on treatment with low valence state titanium. Reagents prepared by treatment of titanium trichloride in tetrahydrofuran with lithium aluminum hydride [205], with potassium [206], with magnesium [207], or in dimethoxyethane with lithium [206] or zinc-copper couple [206,209] convert ketones to alkenes formed by coupling of the ketone carbon skeleton at the carbonyl carbon. Diisopropyl ketone thus gave tetraisopropylethylene (yield 37%) [206], and cyclic and aromatic ketones afforded much better yields of symmetrical or mixed coupled products [206,207,209]. The formation of the alkene may be preceded by pinacol coupling. In some cases a pinacol was actually isolated and reduced by low valence state titanium to the alkene [206] (p. 118). 

There are many electrophiles which not only terminate living polymer chains but also produce end-group substitution. For example, macromolecules with hydroxyl, carboxyl, thiol, or chlorine termini can be prepared by reacting living polymers with such compounds as epoxides, aldehydes, ketones, carbon dioxide, anhydrides, cyclic sulfides, disulfides, or chlorine (15-23). However, primary and secondary amino-substituted polymers are not available by terminations with 1° or 2° amines because living polymers react with such functionalities (1.). Yet, tert-amines can be introduced to chain ends by use of -N-N-di-methylamino-benzaldehyde as the terminating agent (24). 

The formation of organic peroxides as the primary intermediates in the oxidation of hydrocarbons has been definitely established. The degradation of these peroxides to aldehydes, ketones, carbon oxides, and olefins has also been experimentally proved. These facts bring the oxidation of hydrocarbons directly into line with the simpler and better known operations of chlorination, bromination, and nitration. 

Chlorine bleaches react with more chromophores than oxygen bleaches. They react irreversibly with aldehydes, alcohols, ketones, carbon-carbon double bonds, acidic carbon-hydrogen bonds, nitrogen compounds, sulfur compounds, and aromatic compounds. 

Hydroacylation of carbonyls or alkenes by aldehydes is well known. Hydroacylation of an activated ketone (85) by benzaldehyde has now been reported, giving a new asymmetric centre at the ketone carbon (86).257 In a metal-free procedure, the reaction... 

The phosphate triester reacts with a range of sulfur nucleophiles that add to the carbon a to the ketone and open the six-membered phosphate ring. Thiourea adds not only to the a-carbon, but also to the ketone carbon, resulting in elimination of the ketone oxygen as water, a reaction sequence that mimics the conversion of the Moco precursor to a 1,2-enedithiolate (Eq. 7). 

The IUPAC rules for naming ketones append the suffix -one to the parent name. The position of the ketone carbon is indicated by a locant number. Figure 11.37 gives three nomenclature examples of ketones. The simplest ketone, propanone, is commonly known as acetone. Acetone is an excellent solvent for most organic compounds and is the main ingredient in fingernail polish remover. Acetone is one of the ketone bodies that build up in the bloodstream from excessive metabolism of fats. Because ketones typically have a sweet taste and odor, this can give a patient with ketosis a characteristic acetone breath. ... 

Butadiene)zirconocene reacts with metal carbonyls in a similar way as with ketones. Carbon-carbon coupling between a butadiene terminus and the carbonyl carbon atom occurs readily to yield a metallacyclic product, only that generally a metallacyclic n-allyl metallocene system is obtained from the reactions with metal carbonyls.8 Sometimes, O-zirconated Fischer-type carbene complexes are readily formed in this way that cannot be easily obtained by other routes. A typical example is the... 

The alternative route to this cyclic dicarbonyl—Dieckmann condensation—would be a bad choice in this case. Dieckmann condensation works well for five- and six-membered rings, reasonably well for seven-membered rings, but not very well at all for eight-membered rings. The yield is almost exactly half what the ketone-carbonate reaction gives. 

Various substitutions of hydrogen at positions 3 and 4 in -lactams can be performed with electrophilic reagents. The 3-position is activated by the carbonyl group. Alkylation at the 3-position is readily executed via the enolate with alkyl halides, aldehydes, ketones, carbon dioxide, etc. A carboxyl group at C(4) as in 79 does not interfere, the dilithium salt being alkylated at C(3) with excellent stereocontrol, giving the /ra j-disubstituted lactams 80. Hydrolysis leads to -alkyl aspartic acids 81. 

The reaction proceeds by addition of acetylide anion to the carbonyl group and occurs with equal probability from either side of the planar ketone carbon. 

Strategy To identify the carboxylic acid chloride used in the Friedel-Crafts acylation of benzene, break the bond between benzene and the ketone carbon and replace it with a -Cl. 

All of the products have an -OH and a methyl group bonded to what was formerly a ketone carbon. 

Give to the aldehyde or ketone carbon the number " 1", and count two carbons away from the carbonyl carbon. The double bond in the a, 3-unsaturated starting material connected the carbons numbered "2" and "3". 

Attempts to prepare a j -diazenyl-a -diazo ketone [carbon tether (C) , n = 1]. Formation of 6,6-dimethyl-2-phenyl-l,2-diazabicyclo[3.1.0]hexan-3-one (59)... 

Selenium-stabilized carbanions behave as excellent nucleophiles and react with primary alkyl bromides or iodides, allylic and benzylic bromides, epoxides, oxeta-nes, disulfides, trialkylsilyl chlorides, aldehydes, ketones, carbon dioxide, dime-thylformamide, acid chlorides or alkyl chloroformates. With conjugated enones, in the presence of HMPA as cosolvent, the 1,4-addition product is essentially obtained. 

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