Many aldehydes are important components of natural flavours. They are used in food, cosmetic, and biomedical industries in large amounts. Plant cells or microorganisms carry out their production by biotransformation, which is one of the biotechnological methods that allow them to be defined as 'natural'. Cell cultures of Silybum marianum and Peganum harmala have been studied with a view to in...

an efficient one pot multi component synthesis of 1, 4-polyhydroquinoline derivatives through unsymmetrical hantzsch reaction using lanthanum chloride heptahydrate (lacl3.7h2o) from an aromatic aldehyde, ethyl acetoacetate, dimedone and ammonium acetate as a nitrogen precursor in ethanol at room temperature is described. in the present work we report lanthanum chloride heptahydrate remarkably n...

Here we describe a preliminary investigation on the ability of natural keratin to catalyze the nitroaldol (Henry) reaction between aldehydes and nitroalkanes. Both aromatic and heteroaromatic aldehydes bearing strong or moderate electron-withdrawing groups were converted into the corresponding β-nitroalcohol products in both DMSO and in water in the presence of tetrabutylammonium bromide (TBAB)...

a facile and efficient method for the preparation of 1,1-diacetates of aldehydes is improved. the acidified kaolin with sulfuric acid (2 % w/w) catalyzed 1,1-diacetates formation from aldehydes in solvent-free conditions. both aromatic and aliphatic aldehydes gave high yields (85-95 %) of the corresponding 1, 1-diacetates. advantages of this method are the use of inexpensive and selective catal...

a facile and efficient protocol for the synthesis of 1,8-dioxo-octahydroxanthenes has been developed by one-pot knoevenagel condensation, michael addition and cyclodehydration reaction of dimedone (active methylene carbonyl compound) with aromatic aldehydes in the presence of iron (iii) sulfate hydrate as a solid acidic catalyst under solvent-free conditions. various aromatic aldehydes were uti...

Many aldehydes are important components of natural flavours. They are used in food, cosmetic, and biomedical industries in large amounts. Plant cells or microorganisms carry out their production by biotransformation, which is one of the biotechnological methods that allow them to be defined as 'natural'. Cell cultures of Silybum marianum and Peganum harmala have been studied with a view to in...

1,8-dioxo-decahydroacridines have been synthesized by the three-component reaction of aromatic aldehydes, aromatic amines (or ammonium acetate), and dimedone in the presence of sulfonic acid functionalized nanoporous silica (sba-pr-so3h) under solvent-free conditions. excellent yields, short reaction times, mild reaction conditions, and easy work-up procedures are advantages of this green method.

(Diacetoxyiodo)benzene has been used as an efficient catalyst for an improved and rapid one-pot synthesis of biscoumarin derivatives in excellent yield under reflux condition using water as a environmentally benign reaction medium. This aqua mediated Knoevenagel condensation of various aromatic and hetero-aromatic aldehydes with 4-hydroxycoumarin using catalytic amount of (diacetoxyiodo)benzene...

A green and convenient method for the synthesis of 2-amino-3-phenylsulphonyl-4H-chromenes by a one-pot three-component condensation of 1-naphthol, phenylsulphonylacetonitrile and aromatic aldehydes under solvent-free conditions using potassium phosphate tribasic trihydrate as an efficient catalyst is described. The reaction of 1-naphthol with phenylsulphonylacetonitrile and various aromatic...

A novel Lewis acid catalyzed Prins/pinacol cascade process has been developed for the synthesis of 7-substituted-8-oxaspiro[4.5]decan-1-ones in good yields with excellent selectivity. This is the first example of the synthesis of oxaspirocycles from aldehydes and 1-(4-hydroxybut-1-en-2-yl)cyclobutanol through a cascade of Prins/pinacol rearrangement. This method is applicable to a wide range of...