scispace - formally typeset

Journal ArticleDOI

Thermal rearrangement of 4-cyano-2,3-dihydro-5-ethoxy-3-methyl-3-(4-oxo-4H-1- benzopyran-3-yl)furans: a reversed alkoxycarbonylcyclopropane → 5-alkoxy-2,3-dihydrofuran transformation

01 Jan 1989-Journal of The Chemical Society, Chemical Communications (The Royal Society of Chemistry)-Iss: 22, pp 1784-1785

AbstractThe title dihydrofurans (3f, R1= H, Me, and Cl), prepared from the α-cyano-ester (1e) and diazomethane, thermally rearrange to the cyclopropanes (4f) in predominantly Z-isomeric form.

...read more


Citations
More filters
Journal ArticleDOI
Abstract: The Chemistry and application of the title aldehyde and some simple derivatives thereof are reviewed.

40 citations

Journal ArticleDOI
17 Aug 2021
Abstract: The literature data on the methods of synthesis and reactivity of electron-deficient 3-vinylchromones containing electron-withdrawing groups at the exo-cyclic double bond are summarized and systematized for the first time. The main methods for obtaining these compounds are Knoevenagel condensation, Wittig reaction, and palladium-catalyzed cross-couplings. The most important chemical properties are transformations under the action of mono- and dinucleophiles, ambiphilic cyclizations, and cycloaddition reactions. The cross-conjugated and polyelectrophilic dienone system in 3-vinylchromones provides their high reactivity and makes these compounds valuable building blocks for the preparation of more complex heterocyclic systems. Chemical transformations of 3-vinylchromones usually begin with an attack of the C-2 atom and are accompanied by the opening of the pyrone ring followed by recyclization, in which the carbonyl group of chromone, an exo-double bond or a substituent at it can take part. The mechanisms of the reactions are discussed, the conditions for their implementation and the yields of the resulting products are indicated. This review focuses on an analysis and generalization of the knowledge that has accumulated on the chemistry of electron-deficient 3-vinylchromones, mostly over the past 15 years.
Journal ArticleDOI
Abstract: The title dihydrofurans (3f, R1= H, Me, and Cl), prepared from the α-cyano-ester (1e) and diazomethane, thermally rearrange to the cyclopropanes (4f) in predominantly Z-isomeric form.