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.     

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.     

Synthesis of new enantiopure trans-3,4-diaminocaranes from (+)-3-carene

A synthetic strategy to obtain new enantiopure trans-3,4-diaminocaranes derived from (+)-3-carene via a stereoselective methodology is described. The stereoselective preparation of 3,4-α-carene- or 3,4-β-carene-epoxide is followed by a ring opening by sodium azide to obtain the azido-alcohols. Subsequent cyclization affords the corresponding aziridine diastereoisomers, which are converted to azido amines by opening of the aziridine rings by sodium azide and then reduced to the final diamine diastereoisomers. The absolute configurations of the final diamines and of novel intermediates are established by ¹H NMR spectra correlated with conformational analysis supported by molecular modeling.     

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     

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.     

Synthesis of caranoids with two sulfide functions from 3-carene α- and β-sulfides

A convenient method has been developed for obtaining 3-carene α- and β-sulfides from which isomeric 4-RS-carane-3-thiols have been obtained by the nucelophilic addition of thiols under the conditions of base catalysis. The S-alkylation of the latter has formed the corresponding 4-RS-3-R'S-caranes. A high degree of regio- and stereoselectivity of the reactions studied has been found.     

Synthesis of amino derivatives of caranol by the addition of cyclic amines to 3-carene oxides

Addition reactions of cyclic amines (morpholine, piperidine) to oxides of 3-carene in the presence of water have been studied. The reactions take place regio- and stereoselectively with the formation of amino derivatives of the carane series.S. V. Kurashov Kazan' State Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 203–208, March–April, 1992.     

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.     

Synthesis of sulfide derivatives of the carane series by reactions of 3-carene oxides with functional mercaptans

The reaction of 3-carene oxides with functional mercaptans under the conditions of basic catalysis takes place regio- and stereoselectively and is a convenient method of obtaining polyfunctional derivatives of 3-carene and the products of their chemical transformations (hydroxyethylthiocaranols, carboxyalkylthiocarenols, carane thiolactones). Together with the products mentioned, a new type of bicyclic, terpenes — bis-hydroxycaranyl) sulfides — is formed in th3ese reactions.S. V. Kurashov Kazan' State Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 193–198, March–April, 1991.     

Hydroxymercuration-demercuration of 2-carene

Conclusions trans-3-Caranol, a-terpineol, p-5-methene-1,8-diol, and p-6-menthene-5,8-diol are formed in the hydroxymercuration-demercuration of 2-carene.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1049–1052, May, 1979.     

Synthesis and transformation of novel cyclic β-amino acid derivatives from (+)-3-carene

The regio- and stereoselective addition of chlorosulfonyl isocyanate to (+)-3-carene 1 resulted in β-lactam 2, which was converted to N-Boc-β-amino acid 4, β-amino ester 7, and carboxamide derivatives 18 and 20 via N-Boc activation and mild ring opening. The corresponding β-amino ester 7 was transformed to 2-thioxopyrimidin-4-one 11 and 2,4-pyrimidinedione 13. LAH reduction of 5 and 7 resulted in amino alcohols 6 and 8. The reaction of 8 with phenyl isothiocyanate, followed by cyclisation, furnished 1,3-oxazine 15.     

Synthesis of new chiral Schiff bases from (+)-2-carene

New chiral Schiff bases were synthesized through tricyclic 2-azetidinones as key intermediate products which were obtained by reaction of (+)-2-carene with chlorosulfonyl isocyanate.     

The conformation of 3-acetyl-Δ3-carene and 3-carene-7-al

Conclusions The conformations of 3-acetyl-³-carene and 3-carene-7-al were established on the basis of the spectral data and molar Kerr constants.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 994–998, May, 1971.     

Products of the catalytic liquid-phase oxidation of 3-carene

The liquid-phase oxidation of 3-carene in the presence of various catalytic systems has been studied. The possibility has been shown of the directed preparation of 3-carene oxide, of ketones with a carane skeleton and a 7-membered ring, or of aromatic tertiary alcohols.Institute of Physical Organic Chemistry, Academy of Sciences of the Belorussian SSR, Minsk. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 328–334, May–June, 1991.     

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.