Ketones aliphatic unsaturated

Nitriles have good resistance to oil, aliphatic and aromatic hydrocarbons and vegetable oils, but are swollen by polar solvents such as ketones. The unsaturated main chain means that protection against oxygen, ozone and UV light is required. 

Methyltrioxorhenium has been found to catalyse the oleflnation of ketones with ethyl diazoacetate in the presence of triphenylphosphane.20 The optimized system allows the oleflnation of aromatic, aliphatic, unsaturated, cyclic, and trifluoromethyl ketones. 

The following tables are intended to include all the reductions with aluminum alkoxides which were reported prior to February, 1943, although some examples doubtless have been overlooked. Table I lists the reduction of aldehydes, which have been subdivided into (a) aliphatic aldehydes and (b) alicyclic and aromatic aldehydes. Table II lists the reduction of ketones, which have been classified as (a)-satu-rated and unsaturated aliphatic ketones, (b) aromatic ketones, (c) alicyclic ketones, (d) unsaturated alicyclic and aromatic ketones, (e) a- — halogen substituted ketones, (f) diketones, (g) protected diketones, (h) alcoholic and phenolic ketones (and ethers or esters of these), and (i) keto esters. 

Applicability Particularly accurate for the following families acetates, aliphatic ethers, halogenated compounds, dicarboxylic acids, ketones, aliphatic alcohols, aliphatic acids, propionates and butyrates, and unsaturated aliphatic esters. 

Twenty-two pheromones and kairomones and two synthetic analogues are now listed in The Pesticide Manual (Tomlin, 2000). Most of them are long aliphatic unsaturated compounds, with substituents containing oxygen, e.g., esters, alcohols, ketones, and aldehydes. 

This reagent is commercially available and is presently used for many thionations of carbonyl-containing compounds. This is very versatile and efficient, thionating reagent for aromatic, aliphatic, unsaturated, and heterocyclic carboxamides. Lawesson s reagent can thionate carboxamides in the presence of many functional groups. Treatment of 3-A -acylamino ketones with 1 yielded 4//-l,3-thiazine derivatives 2 and 3-A -thioacylamino ketones 3, respectively. By changing the concentration of 1, selective product has been obtained. The 4/f-l,3-thiazines 2 have been produced predominantly when 1 equiv. of 1 was used, while with 0.5 equiv. of 1 the thioamides 3 have been mainly produced (Scheme 2). ... 

Surface modifications of polymers is brought about by the introduction of alcohol functionality, e.g., poly(tetrafluoroethylene-co-hexafluoropropylene) on reduction with sodium naphthalide in THF results in an unsaturated modified surface layer, the thickness of which is controlled with reaction time and temperature. The air sensitive surface contains alcohols, ketones, aliphatic C-H bonds in addition to C=C and C C. The more alcoholic groups are introduced by hydroboration-oxidation, but the esterification leads to the formation of ester in lower yield. This reveals that the reactivity of OH group is similar to hindered alcohols. The reactivity of the surface can be enhanced by chain extension of secondary surface alcohols with ethylene oxide to form a surface containing primary alcohols groups separated from the polymer backbone by C-2 spacer. On the other hand, primary alcohols are directly introduced to the surface by reaction of the reduced layer with 9-BBN, followed by carbonylation and reduction [5]. 

Claisen-Schmidt reaction. Aromatic aldehydes condense with aliphatic or mixed alkyl-aryl ketones in the presence of aqueous alkali to form ap-unsaturated ketones ... 

If ethoxyacetylene is allowed to react in an anhydrous system with aliphatic ketones in the presence of boron trifluoride etherate, the unsaturated acid is obtained directly. This variation apparently has not yet been tried on steroids. 

Several improved methods for the preparation of known unsaturated azlactones as well as some interesting new compounds of this type have been reported. Crawford and Little observed that the direct use of 2-phenyl-5-oxazolone (1) in the Erlenmeyer reaction gave much improved yields (35-74%) of unsaturated azlactones with aliphatic aldehydes and with ketones such as acetone and cyclohexanone [Eq, (1)], The usual procedure of mixing a carbonyl compound, hippuric acid, acetic anhydride, and sodium (or lead) acetate affords poor yields in the aliphatic series. 

A range of electron-withdrawing groups on the nitrogen - N-P(0)Ph2, N-tosyl, and N-SES, for example - were tolerated. Imines derived from aromatic, heteroaromatic, unsaturated, and even aliphatic aldehydes and ketones were employed... 

The addition of HCN to aldehydes or ketones produces cyanohydrins. This is an equilibrium reaction. For aldehydes and aliphatic ketones the equilibrium lies to the right therefore the reaction is quite feasible, except with sterically hindered ketones such as diisopropyl ketone. However, ketones ArCOR give poor yields, and the reaction cannot be carried out with ArCOAr since the equilibrium lies too far to the left. With aromatic aldehydes the benzoin condensation (16-54) competes. With oc,p-unsaturated aldehydes and ketones, 1,4 addition competes (15-33). Ketones of low reactivity, such as ArCOR, can be converted to cyanohydrins by treatment with diethylaluminum cyanide (Et2AlCN see OS VI, 307) or, indirectly, with cyanotrimethylsilane (MesSiCN) in the presence of a Lewis acid or base, followed by hydrolysis of the resulting O-trimethylsilyl cyanohydrin (52). The use of chiral additives in this latter reaction leads to cyanohydrins with good asymmetric... 

The base-catalysed reaction of a-bromo-a,P-unsaturated ketones with aliphatic nitro compounds leads to 2-isoxazoline A-oxides by tandem conjugate addition-ring closure (Scheme 5) <95JOC6624>. A -Acyl-3-isoxazolin-5-ones are transformed into oxazoles by photolysis or by flash vacuum pyrolysis (Scheme 6) <96TL675>. 

Both aliphatic and aromatic terminal alkynes reacted with aliphatic aldehydes giving exclusively a mixture of ( ,Z)-1,5-dihalo-1,4-dienes and disubstituted ( )-a,p-unsaturated ketones, the former being the major products in all cases. When nonterminal aromatic acetylenes were used, the trisubstituted ( )-a,p-unsat-urated ketones were the exclusive compounds obtained. The procedure was not valid for ahphatic and unsaturated alkymes. However, the catalytic system was found to be compatible with alcohols and their corresponding acetates although limited yields were obtained. 

An unusual reaction was been observed in the reaction of old yellow enzyme with a,(3-unsat-urated ketones. A dismutation took place under aerobic or anaerobic conditions, with the formation from cyclohex-l-keto-2-ene of the corresponding phenol and cyclohexanone, and an analogous reaction from representative cyclodec-3-keto-4-enes—putatively by hydride-ion transfer (Vaz et al. 1995). Reduction of the double bond in a,p-unsaturated ketones has been observed, and the enone reductases from Saccharomyces cerevisiae have been purified and characterized. They are able to carry out reduction of the C=C bonds in aliphatic aldehydes and ketones, and ring double bonds in cyclohexenones (Wanner and Tressel 1998). Reductions of steroid l,4-diene-3-ones can be mediated by the related old yellow enzyme and pentaerythritol tetranitrate reductase, for example, androsta-A -3,17-dione to androsta-A -3,17-dione (Vaz etal. 1995) and prednisone to pregna-A -17a, 20-diol-3,ll,20-trione (Barna et al. 2001) respectively. 

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