A number of partially methylated aldoses were derivatized to their trimethylsilylated diethyl dithioacetals, and the products were analyzed by gas chromatography. The use of a capillary column coated with silicone SF-96 allowed resolution and quantification of these sugar derivatives. Gas chroma...

Aldose diethyl dithioacetals react with 1.2 equivalents of 1-ethoxycyclohexene or 2-methoxypropene in N,N-dimethylformamide at 0° with p-toluenesulfonic acid as catalyst to give the five-membered ring acetal attached to the two terminal oxygen atoms as the major product in every case. In most i...

The combination of 1,4-benzoquinone and a catalytic amount of NaI was found to be effective for the deprotection of dithioacetals. The reactions proceeded efficiently under mild, near-neutral reaction conditions, producing a wide range of aryl and alkyl aldehydes and ketones generally in high yi...

3,4,5,6-Tetra-O-benzoyl-d-glucose diethyl dithioacetal (2) reacts with ethanethiol under acidic conditions to afford 3,4,5,6-tetra-O-benzoyl-2-S-ethyl-2-thio-d-mannose (3), the stereochemistry at C-2 of which has been assigned by chemical conversions on its debenzoylated derivative, the crystall...

Acid-catalyzed rearrangements of terminal mono-O-isopropylidene derivatives of some aldose diethyl dithioacetals in N,N-dimethylformamide have been studied. The 4,5-O-isopropylidene derivatives of d-arabinose and d-xylose diethyl dithioacetal respectively rearrange to the 2,3- and a mixture of t...

Some novel prolinal dithioacetal derivatives have been synthesized and applied as the organocatalysts for the direct Michael addition of ketones and aldehydes to nitroalkenes. High enantioselectivities and diastereoselectivities have been obtained in both organic and aqueous media (dichlorometha...

The action of Pd(AcO)2 on the imines C6RmH5-mCHN(CH2)nC6H5 have been studied. Five-membered endo metallacyles were obtained from the imines 1a (R = 3,5-F2, n = 0), 1b (R = 3,5-F2, n = 1), 1c (R = 3,5-(MeO)2, n = 0) and 1d (R = 3,5-(MeO)2, n = 1), by activation of a C(aromatic)-H bond, in spite...

Exocyclic six-membered cyclopalladated dimers 2a-2c, Download full-size image, have been prepared by reaction of palladium(II) acetate with N-benzylidene-2-phenylanilines 1a-1c, RCH=NC6H4-2-C6H5 {1a, R = 2,6-Cl2C6H3; 1b, R = 2,6-F2C6H3 and 1c, R = 2,4,6-(CH3O)3C6H2}, and a subsequent metathesis ...

Cyclotrimerizations of ethynyl N-methyliminodiacetic acid (MIDA) boronate (1) with 1,6-diynes 2 have been studied, using three different catalysts (based on ruthenium, rhodium, and iridium) and variable reaction conditions. Successful cyclotrimerization reactions were obtained with both Cp*RuCl(...

In this study, three donor-π-acceptor (D-π-A) type unsymmetrical porphyrin-based dyes have been designed and synthesized for dye-sensitized solar cells (DSSCs). The photophysical, electrochemical and photovoltaic properties of the dyes were successfully adjusted by using functionalized arylami...

The novel complexes [LnCoCl2] (Ln = LA − LH), containing the N,N-chelating ligands N,N-bis((1H-pyrazol-1-yl)methyl)aniline (LA), N,N-bis((3,5-dimethyl-1H-pyrazol-1-yl)-3,5-dimethylaniline (LB), N,N-bis((1H-pyrazol-1-yl)methyl)-3,5-dimethylaniline (LC), N,N-bis((3,5-dimethyl-1H-pyrazol-1-yl)methy...

The Raman and infrared spectra of solid methyl-5-amino-4-cyano-3-(methylthio)-1H-pyrazole-1-carbodithioate (MAMPC, C7H8N4S3) were measured in the spectral range of 3700–100 cm−1 and 4000–200 cm−1 with a resolution of 4 and 0.5 cm−1, respectively. Room temperature 13C NMR and 1H NMR spectra fro...

Several 5,5′-substituted-2,4-imidazolidinedithiones, synthesized from aldehydes or ketones, have been purified by HPLC using poly(styrene—divinylbenzene) packings. Purified 5,5′-substituted-2,4-imidazolidinedithiones have been identified in column effluent by UV absorbance and corroborated by...

The synthesis of a potential immunosuppressant, i.e. dimethyl ester of N-mycophenoyl malonic acid was optimized in the reaction of mycophenolic acid (MPA) with amino malonic dimethyl ester in the presence of propanephosphonic anhydride (T3P) as a coupling reagent. The structural properties of th...

Chiral 3-methoxy-2,5-morpholinediones which are cyclic N,O-acetals have proved to be excellent chiral cationic amino acid equivalents, especially if larger nucleophiles are employed. They are easily obtained from dipeptolides formed between chiral α-hydroxy acids and dimethyl amino malonate via...

The free fatty acid receptor 1 (FFA1) is being considered to be a novel anti-diabetic target based on its role in amplifying insulin secretion. We have previously identified several series of FFA1 agonists with different heterocyclic scaffolds. Herein, we describe the structural exploration of o...

Potassium tert-butoxide induced self-condensation of 1-acetyl-2-methyl-cyclopentene leads to 6-methyl-4-(2′-methylcyclopent-1′-enyl)bicyclo[4.3.0]non-3-en-2-one 2 in 35% yield when one equivalent of dimethyl sulfate is added. Dienone 2 undergoes facile autoxidation leading to the corresponding...

1-Acetyl-2-chloroperfluorocycloalkenes and 1-benzoyl-2-chloroperfluorocycloalkenes have been prepared by the coupling of 2-chloroperfluorocycloalkenyl copper reagent with acetyl chloride and benzoyl chloride, respectively. Similarly, 1-chloro-2-(p-nitrophenyl)perfluoro-cyclopentene and -cyclohex...

A new Ni(II) optical chemical sensor (optode) based on immobilizing of 2-amino-1-cyclopentene-1-dithiocarboxylic acid (ACDA) to transparent acetyl cellulose film was developed. The sensor was fabricated by binding ACDA to a cellulose acetate film that had previously been subjected to an exhausti...

Long chain branches (LCB) were added to initially linear polypropylene (PP) using reactive extrusion in the presence of selected organic peroxydicarbonates (PODIC). The LCB structure was confirmed by high temperature size exclusion chromatography combined with on-line intrinsic viscosity measure...