Search

The title compound was synthesized via 1,3-dipolar cycloaddition of diazoacetonitrile and diethyl fumarate.

A synthesis of 2-substituted-1,3-dienes is reported which uses silicon as a control element: Eight aldehydes were converted into α-silyl ketones by treatment with trimethylsilylmethylmagnesium chloride and rapid Collins oxidation. Addition of vinylmagnesium bromide to the resulting α-silyl ketones, followed by Peterson elimination, gave a series of dienes. The route was used to make (4S)-3-methylene-t-[(phenylmethoxy)methoxy]pent-1-ene from (–)-ethyl lactate; low asymmetric induction was observed in the Diels–Alder reactions of this diene with diethyl fumarate and N-phenylmaleimide.

The photochemical reaction between 9-vinyladenine (2) and diethyl fumarate (4) gave an unusual photoadduct, epimers 4 and 5, probably derived from attack of the vinyl group on N-3 and reaction of diethyl fumarate on N-9 and N-6.

A synthetic pathway to 5,6-dihydrovaltrate (I) is described using an asymmetric Diels—Alder reaction between diethyl fumarate and cyclopentadiene as key step (catalyst and product configuration are not specified, yield quant., 95% e.e.).

A variety of Diels-Alder reactions have been performed in supercritical water as a reaction medium. The rapid reaction of Diels-Alder reactions of cyclopentadiene and various electron poor dienophiles such as diethyl fumarate and acrylonitrile is observed in supercritical water, and leads to high yields of clean products without added catalysts.

Aromatic and heteroaromatic aldehydes react with diethyl fumarate or diethyl maleate and tri-n-butylphosphine at room temperature to afford good yields of diethyl arylidenesuccinates. Unsaturated and saturated aldehydes afford cognate products.

3-(Fluoroalkyl)isoxazolidines 6 and -2,3-dihydroisoxazoles 8 have been obtained in enantiomerically pure form with good diastereoselectivity by 1,3-dipolar cycloaddition of diethyl fumarate and dimethylacetylene dicarboxylate, respectively, to the chiral fluorinated nitrone (R)-5. The latter has been prepared from the β-fluoromethyl-β-oxo sulfoxide (RS)-1, by a synthetic sequence where the chiral and enantiomerically pure sulfinyl function acts as a removable source of chirality. Reductive opening of isoxazolidines 6 then afforded amino fluoromethyl diols 7 in good yields.

The Diels-Alder reactions of the ortho-quinodimethane (o-QDM) thermally generated from 2,4-diphenylciclobutapyrimidine with the dienophiles diethyl maleate, diethyl fumarate and dimethyl acetylenedicarboxylate have been investigated. The reaction afforded 5,6,7,8-tetrahydroquinazoline and quinazoline derivatives. While diethyl maleate formed a mixture of cis- and trans-adducts, diethyl fumarate gave only the trans-adduct. The reaction with methyl acetylenedicarboxylate formed a mixture of 5,8-dihydroquinazoline and quinazoline derivatives. © 2006 Bentham Science Publishers Ltd.

Treatment of 3-methylamino-5-phenylthiophene with α,β-unsaturated esters, i.e., methyl acrylate, (E)-methyl crotonate, diethyl fumarate, diethyl maleate and ethyl propiolate, in tetrahydrofuran for several days at reflux gave 1-methyl-3,4-dihydrothieno[2,3-e]pyridin-2-ones 4 and/or 1-methylthieno[2,3-e]pyridin-2-ones 5, depending on the structure of the esters. On the other hand, the same reactions with α,β-unsaturated nitriles such as acrylonitrile and tetracyanoethene, gave the corresponding thiophenes 7 and 10 bearing 2-cyanoethyl and 1,2,2-tricyanoethenyl groups at C-2, respectively. The reaction with (Z)-1,2-dicyanoethene under the same conditions produced the corresponding thiophene 9 bearing the 1,2-dicyanoethenyl group and 1,2-dicyano-5-methylaminobiphenyl.

The reaction of chloro-p-nitrophenylcarbene with acetone to form carbonyl ylide is not reversible.