Synthesis of aurones based on usninic acid

(+)-Usninic acid was brominated at the acetyl group located on the aromatic ring. Aurones were synthesized based on the intramolecular cyclization of monobrominated (+)-usninic acid.     

The thermolysis of α-pinene and verbenone epoxides in supercritical solvents

Thermal transformations of α-pinene and verbenone epoxides were studied in supercritical solvents with complex compositions, including CO₂, lower alcohols (ethanol and isopropanol), and water, over the temperature and pressure ranges 387–575 K and 135–215 atm. The main product from α-pinene epoxide in a supercritical solvent containing water was campholenic aldehyde and pinocamphone; the total content of these products in the reaction mixture was 80%. Suggestions concerning the mechanism of the thermal isomerization of α-pinene epoxide depending on the acidity of supercritical solvents were made. The direction of verbenone epoxide transformations was independent of the presence of water in the mixture. The main identified products were ketoalcohols with para-menthane and camphane frameworks.     

Full-field quantum correlations of spatially entangled photons

Spatially entangled twin photons allow the study of high-dimensional entanglement, and the Laguerre-Gauss modes are the most commonly used basis to discretize the single-photon mode spaces. In this basis, to date only the azimuthal degree of freedom has been investigated experimentally due to its fundamental and experimental simplicity. We show that the full spatial entanglement is indeed accessible experimentally; i.e., we have found practicable radial detection modes with negligible cross correlations. This allows us to demonstrate hybrid azimuthal-radial quantum correlations in a Hilbert space with more than 100 dimensions per photon.     

Oxidation of usninic acid

Reactions of usninic acid with various oxidants were studied. The oxidation occurred at the resorcinol ring. New derivatives of usninic acid were obtained from reactions with per-acids.     

Working group report: Heavy-ion physics and quark-gluon plasma

This is the report of Heavy Ion Physics and Quark-Gluon Plasma at WHEPP-09 which was part of Working Group-4. Discussion and work on some aspects of quark-gluon plasma believed to have created in heavy-ion collisions and in early Universe are reported.     

Smiles rearrangements in a series of berberine analogues containing a secondary acetamide fragment

Smiles rearrangements occurring in the derivatives of the isoquinoline alkaloid, berberine, containing an oxyacetic acid fragment at C-9 are described. Methyl-2-(9-demethoxyberberinebromide-9-yl)oxyacetate reacts with an excess of propylamine followed by sequential aminolysis and Smiles rearrangement leading to 2-hydroxy-N-(berbero-9-yl)-N-propylacetamide in 80% yield. Reactions of berberrubine with secondary amides of bromoacetic acid via Smiles rearrangement give N-substituted 2-hydroxy-N-(berbero-9-yl)acetamides (yields 20–36%). In some cases, the intermediate secondary amides were isolated.     

Methods of the synthesis of A-seco derivatives of pentacyclic triterpenoids

The review considers the main methods for the synthesis of derivatives of A-seco pentacyclic triterpenoids by means of the Baeyer-Villiger reaction, the Beckmann rearrangement, and other oxidation processes.     

Quantitative HPLC determination of main flavonoid content of <Emphasis Type="Italic">Rhododendron adamsii</Emphasis> leaves and stems

The content of main flavonoids from Rhododendron adamsii R. leaves and stems was determined quantitatively using HPLC. It was found that myricetin and quercetin dominated the identified compounds (myricetin, quercetin, dihydroquercetin, rutin) in leaves; dihydroquercetin, in stems (1.1, 1.0, and 2.5 mass% of raw material, respectively). Dihydroquercetin and rutin were found for the first time in R. adamsii. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 26–29, January–February, 2009.