Search results for "Decalin"

Total Synthesis of (-)-Hymenosetin.

2015

The 3-decalinoyltetramic acid (−)-hymenosetin and its N-methyl analogue were prepared in 11 and 8 steps, respectively, from (+)-citronellal using an intramolecular Diels–Alder reaction as the key step. This method represents the first example for the synthesis of a 3-decalinoyltetramic acid with a free NH moiety. The stereochemistry of the title compound, an unnatural diastereomer, and of a decalin building block was studied in detail using circular dichroism spectroscopy in the IR and UV/VIS freqeuncy range. This allowed to determine the absolute configuration of the natural product and to plan the synthetic route.

The Influence of the Fir Absorption on the Dielectric Behaviour of Rigid Polar Molecules in Very Dilute Solutions

1974

In view of the FIR absorption the dielectric loss of ten polar molecules — with different volume between furan and 4-bromobiphenyl — has been measured in very dilute solutions at 11 fixed frequencies over an extended range from 0.3 to 300 GHz. Solvents are heptane, cyclohexane, mesitylene, and decalin. For these rigid polar molecules a second high frequency absorption region with time constants of 1–3 ps can be separated from the predominant Debye absorption. This additional absorption decreases with increasing Debye relaxation time. Various molecular motions contributing to this absorption are discussed.

The synthesis and X-ray study of (η6-benzamide)- and (η6-phenylacetamide)tricarbonyl chromium complexes. Structural effects of the substituent

1994

(η6-Benzamide)tricarbonylchromium and tricarbonyl(η6-phenylacetamide)chromium (1 and 2) have been synthesized from the corresponding amides and chromium hexacarbonyl. Decalin, a mixture of decalin and butyl acetate, and neat butyl acetate have been used as the reaction media. The first system gave best yields. Both amide complexes form adducts with non-complexed molecules of the type [(CO3)CrL] · L through hydrogen bonds, suggested on the basis of 1H and 13C NMR spectroscopy. Similar associations by hydrogen bonds exist in the solid state structure of 3 and 4. The π-donor-acceptor abilities of the substituents on the rings are discussed on the basis of geometrical parameters and 13C NMR dat…

Decalin and Tetralin as Probe Molecules for Cracking and Hydrotreating the Light Cycle Oil

2001

Abstract Cracking of tetralin and decalin was carried out over several zeolites to establish the effect of the pore topology of the catalyst on product distribution. These molecules were chosen as probe molecules, because they indicate which catalyst is the best for cracking or hydrotreating the light cycle oil (LCO) fraction, which is obtained directly from fluid catalytic cracking units. A set of zeolites with medium-sized (ZSM-5, MCM-22, ITQ-2), large (USY, Beta), and ultralarge pores (UTD-1), as well as a mesoporous MCM-41, were used as catalysts at 723 K. The results demonstrate that pore size and topology have a strong influence on diffusion, and consequently, on activity and selectiv…

1981

Refractive indices and refractive index increments of the system polystyrene/trans-decalin were measured under pressures up to 500 bar and at temperatures between 20 and 60°C. The measurements were performed with a new, recently designed interferometer. The results demonstrate a sufficient agreement of the refractive index values measured at different temperatures and pressures with the equations of Eykman and Gladstone-Dale whereas the Lorenz-Lorentz equation indicates larger deviations. The experimental data of the refractive index increment follow none of the refractive index mixture rules. It is therefore recommended to determine refractive index increments at different pressures experi…

1981

A new interferometer has been designed in order to perform measurements of refractive indices and refractive index increments on liquid systems under elevated pressure at different temperatures. The method of measurement, the calibration of the instrument and the treatment of data are described. With a series of test measurements on trans-decalin it is shown that with this instrument reliable results are obtained.