Three‐Component Domino Knoevenagel/Hetero‐Diels–Alder Reaction for the Synthesis of the Amino Sugars 2‐Acetoxyforosamine and 2‐Acetoxyossamine – Experimental and Theoretical Results

Abstract

The three‐component domino Knoevenagel/hetero‐Diels–Alder reaction of nitroacetone (6), formaldehyde and ethoxyvinylacetate (4) leads to dihydropyrans 10 and 11, which after hydrogenation of the double bond as well as consecutive reduction of the nitro group and reductive amination give the desired forosamine‐type 2‐acetoxyamino sugars 21–24 and ossamine‐type 25.

Oxidative Synthesis of α‐Nitroketones from α‐Substituted Malononitrile and Nitromethane Using Molecular Oxygen without Condensation Reagents

“…[4] They are also employed in Knoevenagel condensation reactions. [5] An α-nitroketone also acts as an active 1,3-dipolar intermediate, affording heterocycles like isoxazoles and isoxazolines. [6] The presence of the nitro group makes it an excellent precursor for the preparation of α-amino ketones, [7] β-nitro alcohols, [8] β-amino alcohols [8] and 1,2dicarbonyl compounds.…”

Asymmetric Knoevenagel‐Phospha‐Michael Tandem Reaction Synergistically Catalyzed by Achiral Silanols and Grafted Chiral Amines on Mesoporous Silica

“…Tandem reactions, in which multiple reactions are combined into one synthetic operation, have been widely applied to produce elaborate and/or useful molecules . Enzymes, metal complexes, and small organic molecules are effective catalysts for tandem reactions.…”

Novel Synthesis of 3-Aryl-4-hydroxybenzofurans via Four-Component Reaction from Substituted Nitrostyrenes, Aromatic Aldehydes, Cyclohexan-1,3-diones, and Ammonium Acetate

“…Recently, as a useful building block for the formation of carbon-carbon bond, β-nitrostyrenes were employed in the synthesis of many important heterocyclic compounds. [35][36][37][38][39] The Michael addition of activated methylenes to β-nitro-styrenes is an efficient synthetic tool for the formation of carbon-carbon bond, [40][41][42][43][44][45][46] which provides easy access to synthetically important nitroalkanes, then transformation of the corresponding adducts could yield a variety of useful synthetic intermediates. Just recently we reported a very straightforward one-pot multicomponent synthesis of polysubstituted piperidines using β-nitrostyrenes as essential building blocks with aromatic aldehydes, dialkyl malonates, and ammonium acetate.…”