Synthesis and study of organic nitrates of the heterofunctional series

The first representative of organic nitrates of the oxazoline series, 4,4-dihydroxymethyl-2-(3-pyridyl)-2-oxazoline dinitrate, was synthesized by the reaction ofN-nicotinoyltri(hydroxymethyl)aminomethane trinitrate hydronitrate (1) with a solution of KOH in alcohol. The reactivities of compound1 andN-nicotinoylethanolamine nitrate (nicorandil) in the reaction of intramolecular heterocyclization were compared. The structure of the compound synthesized has been established by X-ray diffraction analysis. For Part 1, see Ref. 1 Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 478–481, March, 1998.     

Pheromones ofColeoptera

Racemic 2,6-dimethyioctyl formate (1), a synthetic analog of the aggregation pheromone of two species ofTribolium beetles, has been obtained in six steps and in 28 % overall yield starting from methyl ethyl ketone, vinyl bromide, and 2-methylpropenal. The key step of the synthesis is the sigmatropic [3,3]-rearrangement of 4-ethyl-2,4-dimethyl-1,5-hexadien-3-ol (5) to 2,6-dimethyl-5-octenal (6).For Part 11 see Ref.1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 773–775, April, 1993.     

Nitropyrazoles

A method for the synthesis of bi-, ter-, and quaterpyrazoles by cyclization ofC-(diformylmethyl)nitropyrazoles with hydrazine has been elaborated. Some of theirC- andN-derivatives have been obtained. The compounds prepared have been characterized by¹H,¹³C,¹⁴N, and¹⁵N NMR spectra.For communication 6, see Ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1941–1945, November, 1993.     

Pheromones of Coleoptera

A ten-step synthesis of a racemic form of 3(Z),1l (S)-dodecen-11-olide (ferrulactone II) has been developed. The synthesis is based on the Cadiot-Chodkiewicz cross-coupling of 4-pentyn-2-ol with 2-propyn-1-ol followed by carbon chain elongation by 3-butyn-1-ol and gives the target lactone in 9.7 % overall yield (based on the starting pentynol). All of the three building blocks used for the chain assembly are easily accessible from acetylene. The protection of OH groups astert-butyl ethers has certain synthetic advantages.For part 12, see Ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2122–2125, December, 1993.     

Z-Stereoselective Peterson olefination of ketones

A highly-stereoselective method (90 % of theZ-isomer) was developed for the Peterson olefination of ketones with nerylacetone (1) as an example. The method is based on the introduction of a PhS group, which is removed after completion of the reaction, at the ketone C(3) atom.DeceasedFor the perliminary communication, see Ref. 10.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 509–516, March, 1995.The authors are grateful to the Russian Foundation for Basic Research (grant No. 94.03.08904) and the International Science Foundation (grant NGO000) for financial support of this work.     

Polyfluorinated hydrazones in organic synthesis

The oxidation of 1,1,1,5,5,5-hexafluoro-4-trifluoromethylpentane-2,3-dione bishydrazone (1) with SeO₂, HgO, and Hg(OAc)₂ was studied. The use of selenium dioxide leads to 1,1,1,5,5,5-hexafluoro-4-trifluoromethylpent-2-ene (2) and C₁₂H₄F₁₈Se₂. 1,1,1,5,5,5-Hexafluoro-4-trifluoromethylpent-2-yne (4) and C₆H₂F₉HgC₆H₂F₉ were obtained by the oxidation of bishydrazone1 with mercuric oxide. The oxidation of compound1 with mercuric acetate in diglyme affords 1,1,1,5,5,5-hexafluoro-4-trifluoromethylpenta-2,3-diene (6). Alkyne4 is isomerized to allene6 at 130 °C. For Part 3, see Ref. 1 Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 677–680, April, 1998.     

Cubane derivatives

New esters of 1,4-cubanedicarboxylic acid, 1,4-(ROCO)₂C₈H₆ (R=Et (3a), Pr (3b), CMe₃ (3c), C₆H₁₃ (3d), CH₂CF₃ (3e), or CH(CF₃)₂ (3f) were synthesized. The structures of esters3a, 3b, 3e, and3f were established by X-ray diffraction analysis. The cubane framework of compound3b is somewhat distorted, whereas the C−C bond lengths and bond angles in the other compounds remain virtually ideal. For Part 1, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 457–462, March, 1998.     

N-Phosphorylated lactams

The phosphorylation ofN-trimethylsilyllactams by phosphorus(III) acid chlorides results in correspondingN-phosphinolactams in high yields. The derivatives thus obtained have been used in the synthesis ofN-phosphoryl- andN-thiophosphoryllactams. The reversibility of the reaction of phosphinolactams has been established.For communication 1 see Ref. 1.Translated fromIzyestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2250–2255, November, 1995.     

Chiral and phase transfer agents

Starting from 1,32,4-di-O-ethylidene-D-glucitol (1), two regioisomeric monoaza-18-crown-6 ethers withC ₂ symmetry were synthesized. A simple route was suggested for the preparation of a diol that is a convenient intermediate for the synthesis of chiral aza-crown ethers from diol1.For Part 7, see ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 782–785, April, 1993.     

Cubane derivatives

Efficient method for the synthesis of cubane-1,4-dicarboxylic and 4-bromocubane-1-carboxylic acid N-(morpholinomethyl)amides has been elaborated. For Part 8, see Ref. 1. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 396–398, February, 2008.     

A novel polyfunctional chiral building block derived from (S)-ethyl lactate. Application to the synthesis of the sex pheromone of the southern corn rootworm (Diabrotica undecimpunctata howardi)

Highly enantiomerically pure (4S, 5E)-4-bromomethylhept-5-enenitrile was prepared from (S)-ethyl lactate by a six-step procedure involving a rearrangement of chiral cyclopropylcarbinol. This product was used for the synthesis of the sex pheromone of the southern corn rootworm (Diabrotica undecimpunctata howardi), (10R)-10-methyltridecan-2-one. For preliminary communication, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 151–155, January, 2000.     

Quantitative <Superscript>2</Superscript>H NMR spectroscopy

The selectivity of deuterium distribution between the nonequivalent positions in 3-carene (1), 4-α-acetyl-2-carene (2), and 4-(1-hydroxyethyl)-2-carene (3) has been measured by ²H-{¹H} NMR spectroscopy at the natural abundance of deuterium. These “H/D-isotope portraits” were shown to be typical of terpenes and terpenoids produced in plants via the biosynthetic DXP pathway. The mechanism of acylation of 1 was studied by the density functional theory method (PBE functional, TZ2p basis set). The six-membered ring in compound 1 is planar. However, the endo attack of electrophiles on this ring is more favorable both kinetically and thermodynamically. It was shown both experimentally and theoretically that the elimination of a hydrogen atom in the second reaction step proceeds stereoselectively at the C(2) atom from the anti position with respect to the three-membered ring and occurs with pronounced nucleophilic assistance from the carbonyl group. For Part 2, see Ref. 1. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1657–1664, August, 2008.     

Syntheses based on anabasine

N-Phenacyl salts of acetyl-, benzoyl-, and methylanabasine were synthesized for the first time. Their reactions with unsaturated carbonyl compounds of the ethylene and acetylene series and acrylonitrile were studied. Methods for the synthesis of 6- and 8-(2-piperidyl)indolizines were developed. For Part 1, see Ref. 1. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 135–145, January, 2008.     

peri-Naphthylenediamines

Tertiary alcohols containing the 4,5-bis(dimethylamino)-1-naphthyl group were synthesized. The carbocations that formed from α-methyl-containing alcohols in an acidic medium underwent smooth El elimination to give the corresponding unsaturated derivatives of the “proton sponge” in good yields. At the same time, the carbocation generated from 4-(α-hydroxybenzhydryl)-1,8-bis(dimethylamino)naphthalene was converted into a benzo-[a]fluorene derivative as a result of a complex reaction which has been previously unknown in the chemistry of “proton sponges.” The structure of the latter derivative was established by X-ray diffraction analysis. For Part 26, see Ref. 1; this paper simultaneously presents Part 5 of the series “Resonance-stabilized α-naphthylmethyl carbocations and derived spiro compounds;” for Part 4, see Ref. 2. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1103–1108, June, 2000.     

(Tetramethylcyclobutadiene)cobalt complexes 7. Mono- and dinuclear arene complexes containing the [(C<Subscript>4</Subscript>Me<Subscript>4</Subscript>)Co]<Superscript>+</Superscript> fragment

The mononuclear arene complexes [Cb*Co(arene)]⁺ (3a–g; Cb* = C₄Me₄; arene is biphenyl (a), diphenylmethane (b), 1,2-diphenylethane (c), diphenyl ether (d), p-terphenyl (e), 1,2-dimesitylethane (f), or 1,3-dimesitylpropane (g)) were synthesized by the reactions of arenes either with the benzene complex [Cb*Co(C₆H₆)]⁺ (1) under visible light irradiation or with the acetonitrile derivative [Cb*Co(MeCN)₃]⁺ (2) in refluxing THF. The reactions of 2 with 1,2-diphenyle-thane, 1,3-dimesitylpropane, and p-terphenyl in a ratio of 2: 1 afforded the dinuclear complexes [Cb*Co(μ-η:η-arene)CoCb*]²⁺ (4c,e,g). The stability of the dinuclear arene complexes was estimated by DFT calculations. The structures of the complexes [3a]PF₆ and [3e]PF₆ ere established by X-ray diffraction. For Part 6, see Ref. 1. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 535–539, March, 2008.     

Triazoles and fused triazoles,III: Facile and efficient synthesis of 2,5-disubstituted-s-triazolo[3,4-b]-1,3,4-thiadiazoles

Summary The development of a facile and efficient method for the synthesis of 2,5-diaryl-s-triazolo[3,4-b]-1,3,4-thiadiazoles4 a–e from the corresponding 3-aryl-4-amino-5-mercapto-s-triazole (2), is described. 3-Aryl-4-arylideneamino-5-mercapto-s-triazoles (3 a–e) were cyclized to compounds4 a–e by heating in nitrobenzene for a few minutes.Part II: See Ref. [11]     

Structures and energies of seleno derivatives of biuret.Ab Initio comparative studies of diselenobiuret, selenobiuret, and selenothiobiuret

Ab initio studies (LCAO-MO method) on conformers of three seleno derivatives of the biuret molecules diselenobiuret [I], selenobiuret [II], and selenothiobiuret [III] were carried out at the Hartree-Fock (HF) and MP2 levels. The molecular geometries of these species were fully optimized at the HF level and characterized by analysis of the harmonic vibrational frequencies using a split-valence triple-zeta basis set augmented by a set ofd polarization functions on heavy atoms andp polarization functions on hydrogen atoms [TZP(d, p)]. The total energies of the HF-optimized structures were calculated at the MP2 (frozen core) level using a larger TZP (2df, 2pd) basis set. The potential energy searches revealed a total of 11 minimum-energy conformers (assigned astrans-trans, trans-cis, cis-trans, andcis-cis) and seven transition-state species for the title molecules. The two predicted conformers for diselenobiuret (Ia=trans-trans andIc=cis-cis) are characterized byC ₂ and the third byC _s symmetry. For selenothiobiuret two forms (IIIa=trans-trans andIIId=cis-cis) possessC ₁ and two (IIIb=trans-cis andIIIc=cis-trans) possessC _s symmetries, respectively. For selenobiuret, four formsIIa=trans-trans (C₁),IIb=trans-cis (C _s),IIc=cis-trans (C ₁), andIId=cis-cis (C₁), were obtained as a result of gradient optimization. Comparison of the relative energies for the considered species indicated that thecis-trans forms are the most stable conformations for all three systems at both the HF and MP2 levels of theory.     

A novel polyfunctional chiral building block derived from (S)-ethyl lactate. Application to the synthesis of the sex pheromone of the southern corn rootworm (Diabrotica undecimpunctata howardi)

Highly enantiomerically pure (4S, 5E)-4-bromomethylhept-5-enenitrile was prepared from (S)-ethyl lactate by a six-step procedure involving a rearrangement of chiral cyclopropylcarbinol. This product was used for the synthesis of the sex pheromone of the southern corn rootworm (Diabrotica undecimpunctata howardi), (10R)-10-methyltridecan-2-one. For preliminary communication, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 151–155, January, 2000.     

Synthesis and transformations of 1,3,5-triazabicyclo[3.1.0]hexanes

The conditions for the condensation of 1,2-nonsubstituted diaziridines with CH₂O and NH₃ (or AlkNH₂) to the corresponding 1,3,5-triazabicyclo[3.1.0]hexanes have been found and 3-phenylsulfonyl, 3-trimethylsilyl, 3-nitroso, and 3-nitro derivatives of the latter have been obtained.For the previous communication, see Ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2091–2095, December, 1993.     

Photochemical isomerization of 2H-imidazoleN-oxides

1,3-Diaza-6-oxabicyclo[3.1.0]hex-3-enes and their 3-oxides were obtained by the photolysis of 2H-imidazole 1-oxides and 2H-imidazole 1,3-dioxides. 1,3-Diaza-6-oxabicyclo [3.1.0]hex-3-ene 3-oxides are thermally unstable and are converted to the starting 2H-imidazole 1,3-dioxides; their further photolysis affords a mixture of stereoisomeric 1,3-diaza-4,7-dioxatricyclo [4.1.0.0^3,5]heptanes.For the previous communication, see Ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2096–2100, December, 1993.