R. El Gharbi

Novel Synthesis of 2‐Oxo‐2H‐Benzopyrano[2,3‐d]Pyrimidines

Abstract The synthesis of novel substituted 3‐cyanoiminocoumarins and corresponding N‐ethoxycarbonyl iminocoumarins is described. The condensation of N‐ethoxycarbonyl‐3‐cyano‐7‐diethylamino iminocoumarin with amines as N‐nucleophiles yields substituted 2‐oxo‐2H‐benzopyrano‐[2,3‐d]pyrimidines having promising optical properties.

A Convenient Synthesis Of 3-Arylcoumarins From Arylacetonitriles

Abstract The condensation of salicylaldehydes with various arylacetonitriles catalyzed by anion-exchange resins such as Amberlite IRA 900, leads to the corresponding 3-arylcoumarins in good yields and selectivity.

Polymer Supported Reagents: Novel Methodology for Selective and General Synthesis of Iminocoumarins

Abstract A selective synthesis of iminocoumarins 3 was accomplished, starting from salicylaldehydes 1 and nitriles 2, by the use of Amberlite IRA 900 resin as a polymeric solid support. The possibility of using various arylacetonitriles enhances the synthetic versatility of this strategy.

Direct Synthesis of α,β-Unsaturated Nitriles in Solid/Liquid Heterogeneous Medium

Abstract α,β-unsaturated nitriles are obtained with high yields by condensation of diversely substituted aldehydes using nitriles in the presence of K2CO3. These basic active species avoids aldolisation generally observed in this type of reaction.

A Simplified Wittig Synthesis Using a Solid/Liquid Transfer Process. IX. Selectivity of the Condensation Reaction of Moderated Ylides with Aldehydes

Abstract Conjugated dienes are obtained selectively and with high yields using aldehydes of various structures. The synthesis is made in a two-phase medium, i.e solid/liquid medium.

A Simplified Wittig Synthesis Using a Solid-Liquid Transfer Process : VI - Synthesis of γ -Unsaturated Alcohols from Aromatic and Heteroaromatic Aldehydes

Abstract Very good yields can be obtained for the synthesis of γ-unsaturated alcohols without degradation of γ-hydroxylated phosphonium salts using the phase transfer technique in low hydrated solidliquid medium.

A Simplified Wittig Synthesis Using A Solid-Liquid Transfer Process : VII - Direct Transformation of Aromatic and Heteroaromatic Aldehydes into Functionalised Allylic Ethers

Abstract Synthesis of allylic ethers from various aldehyde alcohols and β-hydroxylated phosphonium salts was carried out in a single manipulation and with excellent yields.

Mecanisme reactionnel de la condensation de l'anethole avec l'acetaldehyde catalysee par des resines echangeuses d'ions

Resume The condensation of anethole with acetaldehyde leads only three stereoisomers to 4-anisyl-2,4,6-trimethyl-1,3-dioxacyclohexane. A reaction mechanism involving ionic intermediates as a result of the successive condensation of two acetaldehyde molecules is proposed.

Novel Synthesis of Bis-Iminocoumarins

Abstract Reaction of 3-aryl iminocoumarins with diacid chlorides as C-electrophilic reagents under mild conditions novel bis-iminocoumarins in good yields. When the reaction was performed with alkylene dibromides by heating them in toluene in the presence of IRA 900 resin, bis-ether compounds were obtained by way opening the pyranic ring. The structures of the product obtained were characterized by Fourier transform infrared, 1H NMR, 13C NMR, and elemental analysis. GRAPHICAL ABSTRACT

Condensation d'alcenes aromatiques avec l'acetaldehyde catalysee par des resines echangeuses d'ions—II : Stereoisomerisation et synthese de nouveaux dioxa-1,3 cyclohexanes polysubstitues

Abstract The interconversion of the three stereoisomers of 4-anisyl-2,5,6 trimethyl-1,3 dioxacyclohexane, obtained from the condensation reaction between anethole and acetaldehyde, depends on the experimental conditions. In some cases, a reversal to the starting alkene could be observed: such a phenomenon does not seem to have been reported so far in the isomerization reactions of 1,3-dioxacyclohexanes. The data can be accounted for by a reaction mechanism involving various cationic intermediates. New 1,3-dioxacyclohexanes were obtained from acetaldehyde and various aromatic alkenes under mild reaction conditions in the presence of sulfonic ion-exchangers used as catalysts, in good yields and with high selectivity.