Synthesis of new pyrazole and triazole derivatives containing a saturated γ-lactone ring

Russian Journal of Organic Chemistry -     

Synthesis of γ-mercuridinitrohydrocarbons

Summary The denitration of -mercurinitro compounds has been studied and the corresponding organomercury dinitro derivatives have been obtained.     

Synthesis of γ-butyrolactone fused cyclooctene

The expeditious route for the synthesis of γ-butyrolactone fused cyclooctene starting from the γ-butyrolactone fused cyclopentane through bicyclo[4.2.1]nonan-9-one is reported. Retro-Dieckmann’s condensation of bicyclo[4.2.1]nonan-9-one in presence of sodium methoxide and methanol furnished γ-butyrolactone fused cyclooctene in good yield. Surprisingly, the stereochemistry of ring-junction of γ-butyrolactone fused cyclooctene is different from the γ-butyrolactone fused cyclopentane, and the position of new ester group, which were confirmed unambiguously by X-ray analysis.     

Synthesis of Some Novel γ-Spirolactones

Summary. We report on the addition of dialkyl acetylenedicarboxylate to 1-alkylisatins or tryptanthrine in the presence of triphenylphosphine which leads to highly functionalised novel unsaturated -spirolactones.     

A Simple Synthesis of γ-Cyclohomocitral

A simple and efficient synthesis for γ-cyclohomocitral (10), a key and versatile intermediate for the synthesis of some furanosesquiterpenes, is described. The formal total synthesis of (±) Pallenscensone (2) was accomplished.     

Synthesis of Secondary α-Methylene γ-Lactams

N-trimethylsilyl aldimines, on reaction with the isolated organozinc derivative of ethyl α-(bromomethyl) acrylate, afford secondary α-methylene γ-lactams with quite quantitative yields.     

Synthesis of γ-benzyltert-butoxycarbonyl-L-alanyl-D-glutamate and its derivatives

A convenient method of obtaining Boc-L-Ala-D-iGln-OBzl and its amide analogs by condensing the N-hydroxysuccinimidyl ester of Boc-L-Ala with the -benzyl ester ofD-Glu in the presence of NaHCO₃, followed by amidation of the resulting Boc-L-Ala-D-Glu--OBzl, is proposed. The use of l-adamantylamine and octadecylamine as amino components has enabled the corresponding -adamantylamide and octadecylamide of the dipeptide to be obtained.Simferopol' State University, 4 Yaltinskaya ul., Simferopol', Crimea, Ukraine 333036. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 101–103, January–February, 1998.     

Synthesis and Structure of Tetraphenylantimony γ-Alkylacetylacetonates

Tetraphenylantimony -ethylacetylacetonate and -allylacetylacetonate were synthesized by reacting pentaphenylantimony with -ethylacetylacetone or -allylacetylacetone in toluene. Their structures were determined by X-ray diffraction analysis. The coordination polyhedron of the antimony atom is a distorted octahedron. In the tetraphenylantimony -ethylacetylacetonate, the Sb–C bond lengths vary in the 2.156(2)–2.170(1) Å range, the SbOC(1)C(2)C(1")O" heterocycle is symmetric, and the Sb–O and O–C distances are 2.201(1) and 1.284(2) Å, respectively. In the tetraphenylantimony -allylacetylacetonate, the Sb–C bond lengths vary in the 2.159(1)–2.167(1) Å range and the Sb–O(1,2) distances are 2.234(1) and 2.191(1) Å.     

Synthesis of β, γ-Unsaturated Valerolactones

In recent years various attempts have been made to use reagent equivalents¹) in order to effect reactions which are not otherwise accessible by means of conventional reagents. Particularly it is to be noted that synthetic equivalents for unreactive dienophiles, such as carbon dioxide,^2,3,4) ketene,^3,5) allene,⁶⁾ and acetylene,⁷⁾ have greatly extended the scope of the cycloaddition reactions into systems not normally generated by the thermal process.     

Synthesis and certain transformations of γ-nitrosoalcohols

The -nitrosoalcohols (II), (XII), and (IX), respectively, have been synthesized by acid-catalyzed hydrolysis of 2-alkoxyisoxazolidines (I), (Xa, b), (Xla, b), and 3-(dimethoxyamino)-3-trifluoromethylbutanol-1 (VIII). The nitrosoalcohol (II) readily rearranges into the oxime (III), and (XII) is converted into the diol (XIII) by oxidation with atmospheric O₂ and denitrosation. For (IX) and (XII) ring-chain tautomerism with formation of 2-hydroxyisoxazolidines could not be detected by PMR spectroscopy.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1563–1568, July, 1991.     

Synthesis of heterospirans containing a γ-lactone ring

Reactions of α-ketols with diethyl malonate at the molar ratio 2:1 in the presence of K₂CO₃ were investigated. The heterospiranes obtained contained a dihydrofuran and a γ-lactone rings. The optimum conditions for the synthesis of heterospiranes were found by varying the ratio of the initial compounds: α-ketoalcohol (or 2-ethoxycarbonyl-, 2-methoxycarbonyl-, 2-cyano-3,4,4-trimethyl-2-buten-4-olides), diethyl malonate, K₂CO₃, by varying the environment, and also the temperature and the time of the reaction.     

Synthesis of Bioactive Organic-Inorganic Hybrids with γ-Methacryloxypropyltrimethoxysilane

Bioactive organic-inorganic hybrids were synthesized through sol-gel processing starting from -methacryloxypropyltrimethoxysilane. NMR-spectroscopic studies showed the presence of silanol groups (Si–OH) and Si–O–Si bonds. In vitro tests of the hybrids for bioactivity with a simulated body fluid (Kokubo solution) indicated that only calcium-containing hybrids could form apatite on their surfaces. Thus the presence of calcium ions was no less important to deposit apatite than the formation of silanol groups or Si–O–Si bonds.     

Synthesis of γ-Substituted Alcohol with Polymer-bound Amide

With solid phase organic synthesis method(SPOS), polymer-bound N-enoylprolinol(4) was prepared by the attachment of N-enoylprolinol(3) to Merrifield resin and was used for asymmetric Michael additions for the first time. The enantiomeric excess obtained by this method is increased as compared with that obtained by the corresponding solution phase reactions.     

Synthesis of Potential Cytotoxic α-Methylene γ-Lactams

α-Methylene γ-lactones are known to have physiological activity, especially as cytotoxic agents, and are widely found in nature (1). However they are often toxic which makes them inappropriate for cancer treatment.     

Simple Synthesis of γ-Lactones from Olefinic Nitriles

The reaction of substituted 4-pentenonitriles with 50% sulphuric acid at 100 °c afforded γ-lactones in moderate to good yield.     

Synthesis of γ-Polynitrocarboxylic Acids And Derivatives Thereof

A synthesis of new branched -nitrocarboxylic acids and their derivatives (nitriles, amides, trinitroethyl esters) was developed proceeding from the corresponding aldehydes obtained by nitroform or 1,1-dinitroethane addition to 2-(2,2-dinitropropyl)acrylic aldehyde according to Michael reaction.