Ethylidene malonate

Methyl-l//-pyrimido[l,2-a]quinolin-l-one was obtained by heating isopropylidene 2-[l-(2-quinolylamino)ethylidene]malonate in EtOH at 20 °C (00MI40). 

Treatment of an ethylidene malonic ester such as (a) with strong bases results in loss of a proton from the allylic position to produce the ambident ion fb). Alkylation of such carban-ions usually occurs at the carbon bearing the carbonyl groups, resulting in the establishment of a quaternary center and deconjugation of the double bond fc). 

Gould and Jacobs obtained a 70% yield of l-(phenylamino)ethylidene-malonate (301, R — Me, R1 = Ph) with 30% of acetanilide (R — Me, R1 = Ph) in the reaction of diethyl 2-acetylmalonate (R = Me) and aniline at ambient temperature for 3 days (39JA2890). However, in the reaction of acetylmalonate and 3-aminonaphthostyril at ambient temperature for several months, only 2-acetylmalonamate (302) was obtained (39JA2890). 

The method of choice for the reaction of diethyl 2-oxocyclohexylphosphonate with ethyl acrylate involves the use of a catalytic amount of EtONa in EtOH. With these conditions, good yields (69%) of Michael adduct are obtained (Scheme 8.59). ° Use of a molar amount of base in an aprotic solvent results in recovery of only unreacted starting material. The reaction of diethyl 2-oxocyclohexylphosphonate is prone to steric factors because no Michael addition occurs when P-substituted Michael acceptors such as methyl crotonatc or ethylidene malonate are used. °... 

Diastereofacial selection in the conjugate reduction of -y-alkyl-a,/3-unsaturated carbonyl derivatives was shown to proceed differently depending on the reagent used. " For example, ethylidene malonate was reduced with LAH to produce predominantly the flnri-product, while catalytic hydrogenation on Pd/C affords the yn-product (Scheme 12). 

Hydrosilylation of I-vinyl-1-cyclohexene (77) proceeds stereoselectively to give the (Z)-l-ethylidene-2-silylcyclohexane 78, which is converted into (Z)-2-ethylidenecyclohe.xanol (79)[74]. Hydrosilylation of cyclopentadiene affords the 3-silylated 1-cyclopentene 80. which is an allylic silane and used for further transformations[75.75a]. Cyclization of the 1,3,8, lO-undecatetraene system in the di(2.4-pentadienyl)malonate 69 via hydrosilylation gives the cyclopentane derivative 81. which corresponds to 2.6-octadienylsilanc[l8,76]. 

MALONALDEHYDE, NITRO-, SODIUM DERIVATIVE, 32, 95 Malonic acid, 31, 35 33, 20, 62 Malonic acid, ethylidene, diethyl ESTER, 32, 54... 

DIETHYL ETHYLIDENEMALONATE (Malonic acid, ethylidene-, diethyl ester)... 

The reflux condenser is replaced by a Claisen distillation head, and the reaction mixture is distilled until the temperature of the vapor reaches 140°. The residue is transferred to a smaller flask and fractionated through a 30-cm. column packed with glass helices. A low-boiling fraction containing ethylidene diacetate and diethyl malonate is collected first, followed by 79-89.5 g. (68-77%) of diethyl ethylidenemalonate b.p. 102-106°/10 mm. %>5 1.4394 (Note 1). 

Diethyl ethylidenemalonate has been prepared by heating acetaldehyde, diethyl malonate, and acetic anhydride 2 3 by heating the same reagents plus zinc chloride 4 by treating acetaldehyde and diethyl malonate with sodium ethoxide or piperidine 6 and by heating diethyl malonate, ethylidene bromide, and ethanolic sodium ethoxide.6... 

Stereoselective allylic alkylations have been carried out with the aid of palladium catalysts. The 17-(Z)-ethylidene groups of steroids (obtained from the ketones by Wittig olefination) form n-allyl palladium complexes in the presence of copper(n) salts (B.M. Trost, 1974, 1976). Their alkylation with dimethyl malonate anions in the presence of 1,2-ethane-diylbis[diphenylphosphine] (— diphos) gives a reaction exclusively at the side chain and only the (20S) products. If one starts with the endocyclic 16,17 double bond and replaces an (S)-20-acetoxy group by using tetrakis(triphenylphospbine)palladium,the substitution occurs with complete retention of configuration, resulting from two complete inversions (B.M. Trost, 1976). 

DI-Ubutyl ester, 34, 26 ETHYLIDENE, DIETHYL ESTER, 32, 54 Malonic ester, ethoxymagnesium derivative, solution of, 30, 70 Malonic ester synthesis, 30, 7... 

There are two early examples in the literature where apparently an intermediately formed bisacceptor-substituted methylenecyclopropane was attacked by a nucleophile. 2-Bromo-3-(dicyanomethyl)pent-3-ene (22) was converted to (2,3-dimethylcyclopropylidene)malonodini-trile (23) in the presence of an excess of triethylamine in dichloromethane at room temperature. 23 could not be isolated but reacted further with 22 to give 6-ethylidene-l,2,5-trimethyl-spiro[2.4]heptane-4,4,7,7-tetracarbonitrile (24) in 70% yield.Also, treatment of 1-[bis(ethoxycarbonyl)methyl]-2,2-dimethylcyclopropanol or its precursor 3-chloro-3-methyl-butan-2-one with the sodium salt of diethyl malonate in tetrahydrofuran under reflux gave small amounts of adducts such as l,l-bis bis[(ethoxycarbonyl)methyl] -2,2-dimethylcyclo-propane and l-[bis(ethoxycarbonyl)methyl]-l-[(ethoxycarbonyl)methyl]-2,2-dimethyl-cyclopropane via dehydration and nucleophilic attack. ... 

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