(4Z,6Z)-4,6-Bis(4-meth­oxy­benzyl­idene)-2,2-dimethyl-1,3-dioxan-5-one

The title compound, C22H22O5, crystallizes with two independent mol­ecules in the asymmetric unit, both of which possess pseudo-C s symmetry. The central 1,3-dioxanone rings have envelope conformations, with the C atom bearing the two methyl groups at the flap. The benzene rings of the meth­oxy­benzyl­idene units, attached in the 4- and 6-positions on the central 1,3-dioxanone rings, are tilted in the same direction with dihedral angles varying between 8.2 (1) and 18.1 (1)°. The crystal packing is influenced by π-stacking inter­actions of the parallel displaced type [centroid–centroid distance of 3.723 (1) Å for mol­ecule 1 and 3.884 (1) Å for mol­ecule 2, with ring slippages of 1.432 and 1.613 Å, respectively] and the T-shaped type, with the long mol­ecular axes all aligned along [010]

(2E,6E)-2,6-Bis(4-methyl­benzyl­idene)cyclo­hex-3-en-1-one

The title compound, C22H20O, shows an approximately planar cyclo­hexenone ring [maximum deviation = 0.069 (4) Å], with a disordered position of the C=C bond [ratio = 0.71 (2)/0.29 (2)]. The benzene rings of the 4-methyl­benzyl­idene units, attached in the 2- and 6-positions to the cyclo­hexenone ring, are rotated in the same direction by 28.6 (4) and 22.4 (4)°, with respect to the mean plane of the cyclo­hexenone ring [fraction 0.71 (2); maximum deviation = 0.06 (3) Å]. In the crystal, mol­ecules are packed in the manner of a distorted hexa­gonal rod packing with their long axes all aligned along [201]. A number of C—H⋯π inter­actions stablize the crystal structure

rac-3-[(3-Chloro­anilino)(4-chloro­phenyl)meth­yl]thian-4-one

In the title compound, C18H17Cl2NOS, the thio­pyran­one ring adopts a chair conformation, with the substituent in the axial position. The dihedral angle between the two benzene rings is 89.43 (1)°. In the crystal, mol­ecules form inversion dimers through inter­molecular N—H⋯O hydrogen bonds [graph set R 2 2(8)]

rac-3-[(Anilino)(naphthalen-2-yl)­methyl]thian-4-one

In the title compound, C22H21NOS, the thio­pyran­one ring adopts a chair-like conformation with the substituent in the axial position. The relative configuration of the racemic compound is 3R,7S according to the numbering scheme used in this publication. In the crystal packing, centrosymmetric dimers are built up via N—H⋯O hydrogen bonds, with graph set R 2 2(8)

A green, inexpensive and efficient organocatalyzed procedure for aqueous aldol condensations

A facile and general procedure is presented for diethylamine-catalyzed double crossed aldol condensation of cyclic ketones with various aromatic aldehydes under aqueous conditions. Excellent yields of 3,5-bisarylmethylidenes of homocyclic and heterocyclic ketones are achieved in a one-pot procedure. Furthermore, the methodology is efficiently applied to the synthesis of chalcones from their corresponding methyl ketones. In the majority of the cases studied, products precipitate from the reaction mixtures and the medium is recycled in subsequent several reactions without significant loss of activity

Synthesis and fluorescence studies of novel bisarylmethylidene derivatives of 2-methoxy-2-methyl-1,3-dioxan-5-one

The first general procedure is described for the synthesis of novel bisarylmethylidenes of 2-methoxy-2-methyl-1,3-dioxan-5-one 1. Thus, several derivatives of 3 are obtained rapidly in high yields by reacting 1 with different aldehydes in the presence of catalytic quantities of pyrrolidine in EtOH at rt. Upon completion of the reactions, products are obtained directly by spontaneous precipitation avoiding time consuming and expensive chromatographic separations. All products were characterized by proton and carbon NMR spectroscopy methods, and in one case, the proposed structure was elucidated by X-ray crystallography, confirming the Z stereochemistry for the olefinic C=C bonds. Due to showing different colors in solid and solution states, products were studied for their photophysical properties as well.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author