I. V. Il’ina

Acid-Catalyzed Transformations of Pinane Terpenoids. New Prospects

The review discusses recent advances in the field of acid-catalyzed intra- and intermolecular transformations of pinane terpenoids and their oxygen-containing derivatives.

New chiral ligands from myrtenal and caryophyllene for asymmetric oxydation of sulfides catalyzed by metal complexes

From myrtenal and caryophyllene, widespread terpene compounds, three new chiral Schiff bases were prepared suitable for ligands in vanadium ions catalyzed sulfides oxidation to chiral sulfoxides.

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.

Transformations of epoxide derived from nopol over askanite-bentonite clay

Transformations of epoxide derived from nopol in the presence of natural askanite-bentonite clay were studied. The major products of the isomerization in the cold are diols possessing a p-menthane skeleton, which are readily converted into bicyclic ethers when the reaction is carried out at room temperature.

Influenza Antiviral Activity of Br-Containing [2R,4R(S),4aR,7R,8aR]-4,7-Dimethyl-2-(Thiophen-2-YL)Octahydro-2H-Chromen-4-Ols Prepared from (–)-Isopulegol

Influenza A (H1N1) antiviral activity of compounds with an octahydro-2H-chromene skeleton that were prepared by reacting the monoterpenoid (–)-isopulegol and thiophenecarboxaldehyde and its derivatives was studied for the first time. The 5-bromothiophene-2-carboxaldehyde derivative exhibited the greatest antiviral activity.

Transformations of several monoterpenoids in the presence of aldehydes in supercritical solvents

The reactivity of verbenol epoxide and isopulegol in supercritical solvents in the presence of aromatic aldehydes was studied using a flow type reactor and a heterogeneous catalyst (Al2O3) or no catalyst. The intramolecular transformations or interactions of reagents with the solvent prevailed in all cases; the yield of the products of intermolecular reactions of terpenoids with aldehydes was up to 1%. The aldehydes did not interact with verbenol epoxide but produced a considerable effect on the distribution of its isomerization products.

Reaction of sabinene with aldehydes in the presence of montmorillonite K10 clay

Transformations of sabinene catalyzed by montmorillonite K10 clay were studied. The main reaction paths were found to be oligomerization and isomerization. The reaction of sabinene with crotonaldehyde gave rise to several polyfunctional heterocyclic compounds.

Oxidation of α-pinene by atmospheric oxygen in the supercritical CO2—ethyl acetate system in the presence of Co(II) complexes

The reactivity of monoterpene α-pinene in a flow reactor in the presence of cobalt catalyst in a complex supercritical solvent consisting of CO2 and ethyl acetate is studied over the temperature range of 190–320°C and a pressure range of 110–125 atm. It was found that the main isomerization products include compounds with bicyclo[2.2.1]heptane and p-menthane backbones; the reaction is accompanied by partial racemization. The formation of oxidation products is observed in the presence of air, with epoxydation rather than allylic oxidation being the predominant process at the first stage. The oxidized products (campholenic aldehyde, verbenone, pinocamphone) are shown to be formed with a high enantioselectivity; the formation of acetoxylation products is observed at temperatures above 200°C.

Reaction of (−)-cis-verbenol epoxide with aromatic aldehydes over montmorillonite K10 clay

Reactions of (−)-cis-verbenol epoxide with a series of para-substituted benzaldehydes in the presence of montmorillonite K10 gave mixtures of products of intra- and intermolecular transformations, whose composition depended on the initial aldehyde.

Hydrogenation and conformational analysis of (1R,2R,6S)-3-methyl-6-(1-methylethenyl)cyclohex-3-ene-1,2-diol

Hydrogenation of (1R,2R,6S)-3-methyl-6-(1-methylethenyl)cyclohex-3-ene-1,2-diol was studied. Nickel chloride-sodium tetrahydridoborate system turned out to selectively reduce the double bond in the isopropenyl group. The results of conformational analysis of (1R,2R,6S)-3-methyl-6-(1-methylethenyl)cyclohex-3-ene-1,2-diol and its partly and completely hydrogenated derivatives were in a good agreement with the NMR data.