N. G. Kozlov

Synthesis and Dehydration of endo-2-(3-R-Isoxazol-5-yl)-1,7,7-trimethylbicyclo[2.2.1]heptan-exo-2-ols

Abstractendo-2-Ethynyl-1,7,7-trimethylbicyclo[2.2.1]heptan-exo-2-ol reacts with nitrile oxides, yielding endo-2-(3-R-isoxazol-5-yl)-1,7,7-trimethylbicyclo[2.2.1]heptan-exo-2-ols. Treatment of the latter with methanesulfonyl chloride in pyridine leads to dehydration and formation of mixtures of the corresponding 1-(3-R-isoxazol-5-yl)-3,3-dimethyl-2-methylenebicyclo[2.2.1]heptanes and 2-(3-R-isoxazol-5-yl)-1,7,7-trimethylbicyclo[2.2.1]hept-2-enes at a ratio of 2:1.

Synthesis of Some Terpene-Alcohol, Sterol, and Plant Phenol Esters of 4,5-Dichloroisothiazol-3-carboxylic Acid

Previously unknown esters 1b-14b were prepared by reaction of cetyl alcohol 1a, terpene alcohols 2a-6a, sterols 7a-11a, and plant phenols 12a-14a with 4,5-dichloroisothiazol-3-carboxylic acid chloride.

3,4,4-Trichloro-3-butenoates of certain terpenols, sterols, and plant phenols

Esters 1b-15b were synthesized by reacting terpenols 1a-7a, sterols 8a-12a, and plant phenols 13a-15a with 3,4,4-trichloro-3-butenyl chloride.

Salts of Nicotinic Acid with a Series of Substituted Amines

13, e-mail: loc@ifoch.bas-net.by; 2) Institute of Physiology, National Academy of Sciences of Belarus, 220072, Minsk, ul. Akademicheskaya, 28, e-mail: evegn_58@ifoch.bas-net.by; 3) Institute of the Chemistry of New Materials, National Academy of Sciences of Belarus, 220141, Minsk, Staroborisovskii trakt, 36, e-mail: dvas@ns.ichnm.ac.by. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 501-502, November-December, 2003. Original article submitted October 2, 2003.

Peroxyacetylenic Derivatives of Menthol

Peroxyacetylenic menthol derivatives were synthesized by reaction of l-menthone with lithium 3-(tert-alkyldioxy)-3-methyl-1-butynides and were converted into the corresponding acetates by treatment with acetic anhydride. The thermal stability of the products was estimated by derivatography and quantum-chemical calculations.

5,5,6-Trimethylbicyclo[2.2.1]heptan-2-one in the Synthesis of Carbocyclic Analogs of Prostaglandin Endoperoxides

Abstract1,3-Dipolar cycloaddition of nitrile oxides to 5,5,6-trimethyl-exo-2-ethynylbicyclo[2.2.1]heptan-endo-2-ol yields the corresponding 2-(isoxazol-5-yl) derivatives. Opening of the isoxazole ring in the latter gives rise to prostanoid precursors with partially built up or completed side chain. 5,5,6-Trimethyl-3-methylenebicyclo[2.2.1]heptan-2-one reacts with nitromethane in the presence of tetramethylguanidine to afford 5,5,6-trimethyl-exo-3-(2-nitroethyl)bicyclo[2.2.1]heptan-2-one which can be converted into the corresponding nitrile oxide by the action of phenyl isocyanate in benzene in the presence of triethylamine as catalyst. 1,3-Dipolar cycloaddition of the nitrile oxide to ethyl 4-pentynoate yields 3-exo-[5-(2-ethoxycarbonylethyl)isoxazol-3-ylmethyl]-5,5,6-trimethylbicyclo[2.2.1]heptan-2-one. Treatment of the latter with hydroxyl amine leads to formation of the corresponding Z-oxime whose reaction with n-hexyl bromide results in transalkylation of the ester group to afford 3-exo-[5-(2-hexyloxycarbonylethyl)isoxazol-3-ylmethyl]-5,5,6-trimethylbicyclo[2.2.1]heptan-2-one oxime.