Annulation Reactions of Allene-Derived 1,3-Dipole with 3-Substituted-Chromones: Unusual Recognition of 4π-Component in 3-(N-Aryliminomethyl)chromones through [4 + 3] Annulation

Autor:	Rajiv Kapoor, Kamal Kumar, Mohan Paul S. Ishar, and Ashish Kapur
Rok vydání:	2000
Předmět:	Annulation Stereochemistry Allene Organic Chemistry Regioselectivity Biochemistry Adduct Dipole chemistry.chemical_compound chemistry Yield (chemistry) Physical and Theoretical Chemistry Triphenylphosphine 1 3-dipole
Zdroj:	Organic Letters. 2:2023-2025
ISSN:	1523-7052 1523-7060
DOI:	10.1021/ol0000713
Popis:	All-carbon dipole derived by the interaction of triphenylphosphine with allenic ester is able to locate the polarized 2π-component in 3-formylchromones through a regioselective [2 + 3] addition to the C2−C3 π-bond, which is followed by deformylation leading to novel 3a,9a-dihydro-1-ethoxycarbonyl-1-cyclopenteno[5,4-b]benzopyran-4-ones. On the contrary, the dipole recognizes azadiene in 3-(N-aryliminomethyl)chromones through [4 + 3] annulation and initially formed adducts undergo tandem rearrangements to afford novel N-aryl-2,3-dihydro-4-ethoxycarbonylchromano[2,3-b]azepine-6-ones in good yield.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::ba4d090d3d45da2022dd2fb7baa417fc https://doi.org/10.1021/ol0000713 Zobrazit plný text záznamu