Ketone alkyl vinyl

Robinson Annulation Sequential Michael addition/aldol condensation between a ketone enolate and an alkyl vinyl ketone (i.e. MVK) to give a cyclohex-2-en-l-one... 

Typical of these materials are the poly(vinyl thioethers), the poly(vinyl isocyanates), the poly(vinyl ureas) and the poly(alkyl vinyl ketones). Methyl isopropenyl ketone and certain vinylpyridine derivatives have been copolymerised with butadiene to give special purpose rubbers. 

A. number of rutro compounds used m ndturdl product synthesis have been prepared by the n of alkyl halides Some recent examples are summarized m Table 2 4 fi-Nitro carbonyl compounds are important for synthesis of natural products The reaction of alkyl vinyl ketones with sodium nitrite and acetic acid in THF gives thecorrespondmgfi-nitro carbonyl compounds in42-82% ""rhis method is better for the preparation of fi-nitro carbonyl compounds than the nitration of the corresponclmg halides... 

The rate of oxidation/reduction of radicals is strongly dependent on radical structure. Transition metal reductants (e.g. TiMt) show selectivity for electrophilic radicals (e.g. those derived by tail addition to acrylic monomers or alkyl vinyl ketones - Scheme 3.89) >7y while oxidants (CuM, Fe,M) show selectivity for nucleophilic radicals (e.g. those derived from addition to S - Scheme 3,90).18 A consequence of this specificity is that the various products from the reaction of an initiating radical with monomers will not all be trapped with equal efficiency and complex mixtures can arise. 

For the synthesis of quinolines and isoquinolines the classical approaches are the Skraup and the Bischler-Napieralski reactions. The reaction of substituted anilines with different carbonyl compounds in acid medium has been reported to be accelerated under microwave irradiation to give differently substituted quinolines and dihydro quinolines [137]. Although the yields are much better and the conditions are milder than under conventional heating, the acidity of the medium may prevent the preparation of acid-sensitive compounds. Thus, alternative approaches have been investigated. Substituted anilines and alkyl vinyl ketones reacted under microwave irradiation on the surface of sihca gel doped with InCU without solvent [137] to furnish good yields of quinohnes 213 (Scheme 77). 

Fluorochromenes result from the reaction of the Cs salts of salicylaldehydes with the phosphonium triflate 37 (Scheme 24) <0OJCS(Pl)103> and 3-acylchromenes are formed from salicylaldehydes and alkyl vinyl ketones in a chemoselective Baylis-Hillman reaction (Scheme 25) . 

Recently, Trost et al. reported the vanadium-catalyzed addition reaction of 2,3-allenols [180], Here the oxygen in 401 served as an intramolecular nucleophile to attack the center carbon atom of allene to form a vanadium enolate 402. Aldol condensation of 402 with an aldehyde afforded (2-hydroxy)alkyl vinylic ketones 403. 

Diels-Alder reactions between dienes and highly reactive dienophiles such as alkyl vinyl ketones can be carried out using the corresponding acetals in order to prevent polymerization of the dienophile. Activation of the masked dienophiles to undergo ionic [4 + 2] cycloadditions with dienes can be by EGA using the conditions in Scheme 18 [44]. Yields in the range 20 to 85% were obtained depending on the... 

With respect to the above-mentioned unsaturated carbonyl compounds with a double bond and a carbonyl group separated by three carbon atoms (14), it can be stated here that they may be disconnected to an alkyl vinyl ketone and an allylic anion (Scheme 7.5), through an oxy-Cope rearrangement (C/. Scheme 5.22). 

The same group reported that bifunctional thiourea 12 catalyzed the enantiose-lective Michael addition [149-152] of a-alkyl and also a-aryl cyanoacetates to alkyl vinyl ketones and aryl vinyl ketones, respectively, to give the desired... 

Ranu, B.C., Hajra, A. and Jana, U., Microwave-assisted simple synthesis of quinolines from anilines and alkyl vinyl ketones on the surface of silica gel in the presence of indium(III) chloride, Tetrahedron Lett., 2000, 41, 531-533. 

CAUTION All operations should be conducted in an efficient fume cupboard owing to the toxicity of aliphatic nitro compounds and of alkyl vinyl ketones. 

Unsaturated-d-lactones.1 This reagent undergoes conjugate addition to alkyl vinyl ketones in the presence of catalysts such as diisopropylamine, DBU, and various phosphines, particularly tri-n-butylphosphine. DMSO is the best solvent DMF and C H, CN are only slightly less effective. The products are precursors to a,/ -unsaturated-Mactones. 

Alkyltetracarbonylferrates, K+[RCOFe(CO)3]. The reaction of these ferrates with alkyl vinyl ketones provides 1,4-diketones when carried out in dimethyl-acetamide. Addition of 18-crown-6 improves yields. 

Hydroxybenzaldehydes react with alkyl vinyl ketones in the presence of l,4-diazabicyclo[2.2.2]octane (DABCO) to yield 3-acyl-277-chromenes (Scheme 19) <2000J(P 1)1331 >. The reaction proceeds via a Baylis-Hillman type pathway to form the zwitterionic intermediate 61 with subsequent cyclization and dehydration to afford 2-acyl-2H-chromenes (Scheme 19) <20030BC1133>. 

To date, this type of phase-transfer-catalyzed Michael reaction of 28 has been investigated with either acrylates or alkyl vinyl ketones as an acceptor, under the influence of different catalysts and bases. Typical results are listed in Table 4.6 in order to determine the characteristics of each system. 

Enamines of aldehydes react with alkyl vinyl ketones.212 Substituted cyclohexanones may be obtained after hydrolysis. Application of this reaction to a,j8-unsaturated aldehydes leads to substituted glutardialdehydes.269 The ratio of the products from the addition of methyl vinyl ketone to the pyrrolidine enamine derived from jS-decalone depends on the configuration of the decalone.76... 

Alkyl vinyl ketones having the general structure 67 (X = H, Table 8) exhibit different reactive sites, depending on the nature of the substituents and the steric requirements. Vinyl ketobases (for the analogous styryl derivatives see Refs. 353 and 354) are obtained by attack of type A on acyclic or exocyclic unsaturated substrates in acidic medium, or with preformed methyleneimmonium salts. Vinylogous Mannieh bases are... 

A solventless synthesis of substituted quinolines occurs when anilines are reacted with alkyl vinyl ketones in the presence of indium(III) chloride on silica gel and with microwave radiation <03T813>. The mechanism proposed involves Michael addition of aniline to the vinyl ketone followed by cyclization and aromatization under the catalysis of InClj/SiOj. The reactions are fast, clean, and high-yielding. 

Polymerizations of methylmethacrylate initiated by organo-magnesium compounds also give rise to stereoregular products, although the active centre is almost certainly a covalent entity. Nevertheless, considerable similarities exist between these and conventional anionic systems. This is also true of polymerizations of alkyl vinyl ketones initiated by zinc and magnesium alkyls, and progress in this area has also been reported recently. ... 

A simple and eiScient method for the synthesis of 4-alkyquinolines by one-pot reaction of aniline with alkyl vinyl ketone on the surface of SiO2-impregnated InCls under microwave irradiation has been demonstrated by Ranu and his group (Scheme 5.37). 

Sasai and coworkers reported that a chiral BINOL derived amine 16a catalyzed asymmetric aza MBH reaction of N tosyl imines with acrolein and alkyl vinyl ketones [22]. The corresponding aza MBH adducts were obtained in good to excellent yields with high enantiomeric excesses (Table 13.4). Replacing the tPr group with other substituents in amine 16a provided less effective catalysts regarding yield or enantioselectivity [23]. 

Examples of monomers in this category include alkyl vinyl ketones and vinyl bromide both of which dissociate when irradiated with ultraviolet light by the following reactions ... 

In aqueous solution, the PCM method computes an activation enthalpy of 15.3 kcal/mol, which is 46% [3.8 kcal/mol (computed)/8.2 kcal/mol (expected)] of the estimated reduction to a 10.9 kcal/mol activation barrier. In a second comparison, the second-order rate constants between cyclopentadiene and alkyl vinyl ketones have been reported to be 740 times larger in water than in ra-octane [82], Overall, the PCM model lowers the Gibbs activation energies of the NC reaction from benzene to water by 2.0 kcal/mol, which correspond to an aqueous rate increase of ca. 30 times. Therefore despite mirroring the experimental trend in activation barrier reduction with increasing solvent polarity, the PCM method does not fully account for the observed rate of aqueous acceleration. 

Langkettige Carbonsauren durch Michael-Addition an (co-Alkoxycarbonyl-alkyl)-vinyl-ketone (Buch-... 

Poly(l-alkoxyethylene) Poly(alkyl vinyl ether) -[ROCHCH ]-Poly(l-hydroxyethylene) Poly (vinyl alcohol) -[HOCHCH ]-Poly(l-alkanoylethylene) Poly(alkyl vinyl ketone) -[RCOCHCHJ... 

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