Hydroxymercuration-demercuration of 3-carene

Conclusions It was found that Hg(OAc)₂ adds to 3-carene both to the double bond and to the three-membered ring; the formation of-4-caranol and trans-1,8-terpin as demercuration products is in agreement with the trans-addition of the mercury salt to the double bond.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 385–388, February, 1972.     

Products of chlorination of 3-carene by N-chlorosuccinimide

Conclusions The chlorination of 3-carene by N-chlorosuccinimide gave (–)-4-chloro-3 (10)-carene, (–)-3,4-dichlorocarane, (+)-3,4-dichlorocarane, and 2,8-dichloro-p-mentha-1(7),5-diene.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 206–209, January, 1987.     

Purification of molybdenum : volatilisation processes using MoO3

Various volatilisation processes for the purification of MoO₃ were investigated. Of these, fusion Of MoO₃ with NACl at 600°C gave the best results. Thermal analysis of the MoO₃/NaCl and WO₃/NaCl systems illustrates details of the processes involved.     

Modified oxidation of (+)-3-carene by potassium permanganate

The oxidation of (+)-3-carene under the conditions of phase-transfer catalysis has been studied. It has been shown that when the reaction is performed in acetic acid the keto acids (IIa) and (IIIa) and (–)-3-hydroxycaran-4-one (IV) are formed.Institute of Organic Chemistry, Urals Branch, Russian Academy of Sciences, Ufa. Translated from Khimiya Prirodnykh Soedinenii, Nos. 3,4, pp. 338–340, May–August, 1992.     

Oxidation of 3-carene with mercuric acetate

Summary The oxidation of 3-carene with mercuric acetate was studied. The oxidative acetylation of 3-carene with mercuric acetate leads to a less complex mixture of products than oxidation with lead tetraacetate. The main products are p-mentha-l,5-dien-8-ol and, in smaller amount, p-isopropenyltoluene.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 466–475, March, 1965     

Enantioselective epoxidation of electrophilic olefins by using glycosyl hydroperoxides

Anomeric hydroperoxides derived from 3,4,6-tri-O-benzyl-galactose and glucose were used for enantioselective epoxidation of naphthoquinone (12), chalcone (13), (E)-1,2-dibenzoyl ethylene (14) and (E)-iso-butyryl-phenyl ethylene (15). In the presence of sodium hydroxide, the epoxidations showed exceptional high asymmetric induction. The exchange of sodium by a potassium ion resulted in a low asymmetric induction. These results pointed to the crucial role of the counterion and strongly suggested that coordination of the alkaline ion occurs in the transition state of the epoxidation process by both reagents, hydroperoxide and the olefin. Theoretical studies of the reaction mechanism at the DFT B3LYP/6-31G* level fitted very well with experimental results.     

Reaction of 3-carene with perfluoroalkanoic acids

The addition of perfluoroalkanoic acids to 3-carene involves opening of the cyclopropane ring at the peripheral bonds with formation of a mixture of isomeric p-menth-1-en-8-yl and m-menth-1-en-8-yl perfluoroalkanoates. The reaction rate decreases as the length of the perfluoroalkyl radical of the acid increases. Trichloroacetic acid reacted with 3-carene at a lower rate than does trifluoroacetic acid, but the products are analogous p-menth-1-en-8-yl and m-menth-1-en-8-yl trichloroacetates.     

A novel catalyst for hydrazine decomposition: molybdenum carbide support on gamma-Al2O3

An alumina-supported Mo2C catalyst is found to be as active as a conventionally used Ir/gamma-Al2O3 catalyst for catalytic decomposition of hydrazine tested in a monopropellant thruster.     

Peroxo and alkylperoxidic molybdenum(VI) complexes as intermediates in the epoxidation of olefins by alkyl hydroperoxides

Novel oxoperoxomolybdenum(VI) complexes with the general formula MoO(O₂)L₂X₂ (III, L = DMF, HMPT) and MoO(O₂)Cl(ON)L(IV, ON) = pyridin-2-carboxylate (Pic), 8-hydroxyquinolinate (Quin) were prepared from the reaction of Ph₃COOH or H₂O₂ with the corresponding cis-dioxo complexes. In the reaction with Ph₃COOH both oxygen atoms of the peroxo moiety were found, by ¹⁸O labeling experiments, to come from the hydroperoxide. The X-ray crystal structure of MoO(O₂)Cl(Pic)(HMPT) revealed a bipyramidal pentagonal surounding with a rather short OO distance (1.41 Å). Complexes III were found to be more reactive than MoO(O₂)₂,HMPT for the epoxidation of olefins (oxidative cleavage products are consecutively formed) but react by the same cyclic peroxymetalation mechanism. The absence of reaction in the case of complexes IV illustrates the necessity for the metal to possess an equatorial releasable coordination site adjacent to the peroxo group for the oxygen transfer to occur. Catalytic oxidation of olefins using Ph₃COOH gave a selectivity in oxygenated products very different from that using t-BuOOH, and ¹⁸O labeling studies showed that alkyl-peroxidic rather than peroxo species are intermediates in this latter reaction. The mechanism of epoxidation of olefins by alkyl hydroperoxides catalyzed by d⁰ metal complexes is discussed.     

Mechanisms of the stabilization of a molybdenum epoxidation catalyst by nitrogen-containing compounds

Nitrogen-containing compounds have been studied as stabilizing additives for a complex molybdenum catalyst for propylene epoxidation with ethylbenzene hydroperoxide. Introducing the additives increases the half-life period by a factor of 10–14. The effective constants and rates of the decomposition of the catalytic complex in the presence of stabilizing agents have been calculated. Two possible mechanisms of the action of the nitrogen-containing additives have been suggested.     

Biotransformation of (1S)-2-carene and (1S)-3-carene by Picea abies suspension culture

Biotransformation of (1S)-2-carene and (1S)-3-carene by Picea abies suspension culture led to the formation of oxygenated products. (1S)-2-Carene was transformed slowly and the final product was identified as (1S)-2-caren-4-one. On the other hand, the transformation of (1S)-3-carene was rapid and finally led to the formation of (1S)-3-caren-5-one and (1S)-2-caren-4-one as equally abundant major products. The time-course of the reaction indicates that some products abundant at the beginning of the reaction (e.g. (1S, 3S, 4R)-3,4-epoxycarane and (1R)-p-mentha-1(7),2-dien-8-ol) were consumed by a subsequent transformations. Thus, a precise selection of the biotransformation time may be used for a production of specific compounds.     

Synthesis of enantiomericcis-homocaronic acids from (+)-3-carene

The syntheses of the dimethyl ester of (-)-(1R)-cis-homocaronic acid (7 steps, overall yield 43 %) and its antipode, the dimethyl ester of (+)-(1S)-cis-homocaronic acid (5 steps, overall yield 27 %), were performed starting from (+)-3-carene and its derivatives, (+)-4-acetyl-2-carene and (+)-4-acetoxymethyl-2-carene. Oxidative cleavage in the key stages was carried out by ozonization.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 314–318, February, 1995.