Ethyl formate vinyl ketone

The aziridine aldehyde 56 undergoes a facile Baylis-Hillman reaction with methyl or ethyl acrylate, acrylonitrile, methyl vinyl ketone, and vinyl sulfone [60]. The adducts 57 were obtained as mixtures of syn- and anfz-diastereomers. The synthetic utility of the Baylis-Hillman adducts was also investigated. With acetic anhydride in pyridine an SN2 -type substitution of the initially formed allylic acetate by an acetoxy group takes place to give product 58. Nucleophilic reactions of this product with, e. g., morpholine, thiol/Et3N, or sodium azide in DMSO resulted in an apparent displacement of the acetoxy group. Tentatively, this result may be explained by invoking the initial formation of an ionic intermediate 59, which is then followed by the reaction with the nucleophile as shown in Scheme 43. 

As it is known from experience that the metal carbenes operating in most catalyzed reactions of diazo compounds are electrophilic species, it comes as no surprise that only a few examples of efficient catalyzed cyclopropanation of electron-poor alkeiies exist. One of those examples is the copper-catalyzed cyclopropanation of methyl vinyl ketone with ethyl diazoacetate 140), contrasting with the 2-pyrazoline formation in the purely thermal reaction (for failures to obtain cyclopropanes by copper-catalyzed decomposition of diazoesters, see Table VIII in Ref. 6). 

Palladium(II) acetate was found to be a good catalyst for such cyclopropanations with ethyl diazoacetate (Scheme 19) by analogy with the same transformation using diazomethane (see Sect. 2.1). The best yields were obtained with monosubstituted alkenes such as acrylic esters and methyl vinyl ketone (64-85 %), whereas they dropped to 10-30% for a,p-unsaturated carbonyl compounds bearing alkyl groups in a- or p-position such as ethyl crotonate, isophorone and methyl methacrylate 141). In none of these reactions was formation of carbene dimers observed. 7>ms-benzalaceto-phenone was cyclopropanated stereospecifically in about 50% yield PdCl2 and palladium(II) acetylacetonate were less efficient catalysts 34 >. Diazoketones may be used instead of diazoesters, as the cyclopropanation of acrylonitrile by diazoacenaph-thenone/Pd(OAc)2 (75 % yield) shows142). 

EINECS 203-468-6, see Ethylenediamine EINECS 203-470-7, see Allyl alcohol EINECS 203-472-8, see Chloroacetaldehyde EINECS 203-481-7, see Methyl formate EINECS 203-523-4, see 2-Methylpentane EINECS 203-528-1, see 2-Pentanone EINECS 203-544-9, see 1-Nitropropane EINECS 203-545-4, see Vinyl acetate EINECS 203-548-0, see 2,4-Dimethylpentane EINECS 203-550-1, see 4-Methyl-2-pentanone EINECS 203-558-5, see Diisopropylamine EINECS 203-560-6, see Isopropyl ether EINECS 203-561-1, see Isopropyl acetate EINECS 203-564-8, see Acetic anhydride EINECS 203-571-6, see Maleic anhydride EINECS 203-576-3, see m-Xylene EINECS 203-598-3, see Bis(2-chloroisopropyl) ether EINECS 203-604-4, see 1,3,5-Trimethylbenzene EINECS 203-608-6, see 1,3,5-Trichlorobenzene EINECS 203-620-1, see Diisobutyl ketone EINECS 203-621-7, see sec-Hexyl acetate EINECS 203-623-8, see Bromobenzene EINECS 203-624-3, see Methylcyclohexane EINECS 203-625-9, see Toluene EINECS 203-628-5, see Chlorobenzene EINECS 203-630-6, see Cyclohexanol EINECS 203-632-7, see Phenol EINECS 203-686-1, see Propyl acetate EINECS 203-692-4, see Pentane EINECS 203-694-5, see 1-Pentene EINECS 203-695-0, see cis-2-Pentene EINECS 203-699-2, see Butylamine EINECS 203-713-7, see Methyl cellosolve EINECS 203-714-2, see Methylal EINECS 203-716-3, see Diethylamine EINECS 203-721-0, see Ethyl formate EINECS 203-726-8, see Tetrahydrofuran EINECS 203-729-4, see Thiophene EINECS 203-767-1, see 2-Heptanone EINECS 203-772-9, see Methyl cellosolve acetate EINECS 203-777-6, see Hexane EINECS 203-799-6, see 2-Chloroethyl vinyl ether EINECS 203-804-1, see 2-Ethoxyethanol EINECS 203-806-2, see Cyclohexane EINECS 203-807-8, see Cyclohexene EINECS 203-809-9, see Pyridine EINECS 203-815-1, see Morpholine EINECS 203-839-2, see 2-Ethoxyethyl acetate EINECS 203-870-1, see Bis(2-chloroethyl) ether EINECS 203-892-1, see Octane EINECS 203-893-7, see 1-Octene EINECS 203-905-0, see 2-Butoxyethanol EINECS 203-913-4, see Nonane EINECS 203-920-2, see Bis(2-chloroethoxy)methane EINECS 203-967-9, see Dodecane EINECS 204-066-3, see 2-Methylpropene EINECS 204-112-2, see Triphenyl phosphate EINECS 204-211-0, see Bis(2-ethylhexyl) phthalate EINECS 204-258-7, see l,3-Dichloro-5,5-dimethylhydantoin... 

In contrast to these vapour-phase reactions, it has been reported that ketones and aqueous ammonia (or ammonium acetate) in an autoclave give less complex mixtures of pyridines. Crotonaldehyde gives 5-ethyl-2-methylpyridine (570) in up to 59% yield, methyl vinyl ketone gives 2,3,4-trimethylpyridine (571) rather than 2,3,6-trimethylpyridine 1,3,3-trimethoxybutane has been used in place of methyl vinyl ketone (49JA2629). In some cases reverse aldol reactions occur (for example with benzalacetophenone) giving unwanted products. A similar reverse aldol is responsible for the production of triarylpyridines (572) when benzalacetophenones are treated with formamide and ammonium formate (73JA4891). 

The formation of the bicyclic intermediate, VII/157, (Scheme VII/31) was achieved by nucleophilic conjugate addition of tributyltinlithium to cyclohexe-none, reaction of the intermediate ketone enolate ion with a small excess of ethyl vinyl ketone and, subsequently, with a large excess of formaldehyde. The mechanism is analogous to that presented in Scheme VII/9 of Chapter VII. 1. 

Induced pre-dissociation is reported to be a photochemical path to ethane during the irradiation of acetone in the gas phase. ° Irradiation at 193 nm of ethyl vinyl ketone results in the formation of a variety of products such as n-butane, but-l-ene and buta-1,3-diene. The study was used to determine the rate of combination of ethyl radicals to yield butane and of vinyl radicals to afford buta-l,3-diene. ... 

Several structurally different diketones (acetylacetone, methyl 2-oxocyclohex-ane carboxylate) and active methylene compounds (diethyl malonate, ethyl aceto-acetate) and thiols (methyl thioglycolate) underwent clean, fast, and efficient Michael addition with methyl vinyl ketone, acrolein, and methyl acrylate over NaY and Na beta zeolites [88] in high yield (70-80%). The reactions were performed in the absence of solvent, at room temperature, with 1 g catalyst per mmol donor. When HY zeolite was used instead of NaY formation of the desired Michael adduct was low and polymerization of Michael acceptor was the main reaction. 

Acetophenone (252) was converted into the vinyl ketone (232) by the procedure of Girotra et al. Mannich reaction of compound 252 with AA -dimethylamine hydrochloride and p-formaldehyde in refluxing isopropyl alcohol in the presence of a catalytic amount of HCl resulted in formation of the Mannich base (254) in 77% yield. Subsequently, treatment of 254 with aqueous NaOH and methyl iodide in ethyl acetate gave a quaternary salt (255) in 83% yield. On heating in a H20-EtOAc biphasic system, compound 255 underwent a... 

These alkenylation products are easily utilized for the formation of heterocyclic compounds by cyclization reactions. For example, ethyl A -methyl-lV-(3,4-methylenedioxy)benzylglycinate is cyclopalladated regiospecifically at C(6) when treated with Li2PdCl4. The product, the di-p-chloro-bis(AOV-dialkylbenzylamine-6-C,iV)-dipalladium(II) complex 7.19, undergoes a substitution reaction via the insertion of methyl vinyl ketone between the palladium metal and the phenyl carbon atom. The resultant p-aryl-a,p-unsaturated ketone 7.20 is cyclized using anhydrous potassium carbonate in ethanol to the corresponding ethyl iV-methyl-1,2,3,4-tetrahydroisoquinolinium-3-carboxylate 7.21, as shown in Eq. (7.19) [76, 77]. 

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