α-Bromoketones of bicyclo[3.3.1]nonane series

Conclusions The cyclization of bicyclo[3.3.1]nonane -bromoketones gave 3,7-dibromo-2,6-noradamantanedione, whose structure was proved.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1096–1099, May, 1976.The authors express their gratitude to V. N. Leibzon for running the electrochemical reduction of (IV).     

Bicyclo[3.3.1]nonane and its derivatives—IV : Reactions of some carbonyl derivatives of bicyclo[3.3.1]nonane with diazomethane

The reaction of bicyclo[3.3.1]nonane-2,6-dione with diazomethane in situ does not lead to the homologous bicyclo[4.3.1]decane-2,7-dione, but mainly to tricyclo[4.4.0.0^2,9]decan-9-ol-5-one. The structure of the latter was confirmed by the proton NMR spectra measured with an addition of Eu(DPM)₃, A mixture of tricyclo[4,4.0.0^2,9]decan-9-ol-5-one and bicyclo[4.3.1]decane-2,7-dione results when solutions of diazomethane are used. The reaction of bicyclo[3.3.1]nonane-2,6-dione monoethyleneacetal with diazomethane in situ yields predominantly bicyclo[4.3.1]decane-2,7-dione. Under the same conditions bicyclo[3.3.1]nonan-2-one gives with diazomethane in situ only bicyclo[4.3.1]decan-2-one.     

Conformational effects of 1,5,9-substitution in symmetric bicyclo[3.3.1]nonane analogues

The high-level ab initio calculations on several derivatives of bicyclo[3.3.1]nonane, 1-aza- and 1,5-diazabicyclo[3.3.1]-nonanes show the ‘double chair’ (CC) conformer as optimal for all of them, dominating over the ‘boat–chair’ (BC) form. Conformational effects of several substitution types involving positions 1, 5 and 9 are quantified, and their values are found rather transferable.     

Synthesis of adamantane and bicyclo[3.3.1]nonane derivatives with the oxetane moiety

A method of synthesis of 3-hydroxyoxetane esters with adamantane- and bicyclo[3.3.1]nonane-containing carboxylic acids is reported.     

Molecular and crystal structure of indole derivatives fused with substituted bicyclo[3.3.1]nonane

Molecular structures of oxime 6-oxo-indolo[2,3-b]-bicyclo[3.3.1]non-2-en 1 and 6-oxo-(5-methoxy-indolo[2,3-b])-bicyclo[3.3.1]non-2-en 2 were determined by X-ray crystal investigation. It was revealed that oxime 1 has anti-configuration in respect to indole-containing framework, and both compounds adopt half-chair–chair-conformation. The distortion of rings was evaluated by calculation of the ZP- and CP-puckering parameters. The presence of the methoxy-group in compound 2 was found to lead to the changes in molecular packing in comparison with structure 1.     

Synthesis of 1,10-phenanthrolines fused with bicyclo[3.3.0]octane and bicyclo[3.3.1]nonane frameworks

Reactions of bicyclo[3.3.1]nonane-2,6-dione and bicyclo[3.3.0]octane-3,7-dione with 8-amino-7-quino-linecarbaldehyde under basic conditions led to fused nonplanar compounds with one or two 1,10-phenanthroline moieties. The novel heterocyclic systems bicyclo[3.3.1]nonano[2,3-b]bis[1,10]-phenanthroline, cis-bicyclo[3.3.0]octano[3,2-b:7,6-b']bis[1,10]phenanthroline, bicyclo[3.3.1]nona-no[2,3-b:6,7-b']bis[1,10]phenanthroline, and 8H-9,16-methanoindolo[2',3':5,6]cycloocta[1,2-b]bis-[1,10]-phenanthroline have been synthesized and characterized.     

Synthetic approach to preparation of indole derivatives fused with a bicyclo[3.3.1]nonane framework

Starting with Δ¹⁵-17-ketosteroids, applying Normant reaction with allylmagnesium bromide and anionic Cope rearrangement of the formed allyl alcohol, 15α-derivatives of androstane series were prepared. The latter were brought into Wittig reaction with an ylide generated from ethyltriphenylphosphonium bromide, and the product was subjected to ene reaction to provide 15α-substituted pregnanes.     

Synthesis of indoles condensed with a bicyclo[3.3.1]nonane skeleton

Derivatives of mono- and bisindoles condensed with a bicyclo[3.3.1]nonane skeleton were synthesized from bicyclo[3.3.1]nonane-2,6-dione and 6-hydroxybicyclo[3.3.1]nonan-2-one by means of the Fischer reaction.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 315–318, March, 1979.     

Photochemistry of 3,7-Bis(arylmethylene)bicyclo[3.3.1]nonane Derivatives

UV irradiation of trans-trans-3,7-bis(arylmethylene)bicyclo[3.3.1]nonane-2,6-diones leads to their complete or partial transformation into the corresponding cis-cis isomers. Irradiation of trans-trans-3,7-bis(arylmethylene)bicyclo[3.3.1]nonane-2,6-diol in ether in the presence of CuCl results in intramolecular cyclization involving the exocyclic double bonds and one benzene ring to give exo-7endo-10-dihydroxy-2-phenyl-3,4-benzotetracyclo[4.3.3.18,11.01,6]tridecane.     

Mass spectra of some mono- and disubstituted bicyclo [3.3.1]nonane dervatives

Conclusions It was shown that an analogy exists in the decomposition under electron impact of a series of mono- and disubstituted bicyclo[3.3.1]nonane derivatives and the corresponding adamantane derivatives.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 711–715, March, 1977.     

Unique stereochemistry of 3-borabicyclo[3.3.1]nonane derivatives

The conformational equilibrium in solution was examined by NMR spectroscopy for a series of 7-phenyl-3-borabicyclo[3.3.1]nonane derivatives containing various substituents at the boron atom. The structures of these derivatives were studied in the crystalline state (X-ray diffraction analysis) and by quantum-chemical calculations (B3Pw91/6-31G*). The B...Ph transannular interactions corresponding to charge transfer from the system of the phenyl group to the vacant p-orbital of the B atom were demonstrated to be responsible for unique stability of the chair-chair conformation of these derivatives.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1884–1896, September, 2004.     

Conformational analysis of 3-borabicyclo[3.3.1]nonane derivatives

Conformations of 3-borabicyclo[3.3.1]nonane derivatives have been studied by means of ¹H and ¹³C NMR spectroscopy. With the aid of the coupling constants ³J(HH) and ¹³C chemical shifts it has been shown that all the derivatives of 3-borabicyclo[3.3.1]nonane with the trigonal boron atom studied are in a flattened double-chair conformation. In 3-borabicyclo[3.3.1]nonane derivatives with the tetra-coordinated boron atom and substituents at the 7α-position, the chair-boat conformation predominates, the boat conformation being characteristic of the cyclohexane ring; exceptions are the compounds with the internal donor—acceptor bond between the boron atom an 7α-substituent.     

Stereochemical studies—XVIII : Conformational study of heteroanalogues of bicyclo[3.3.1]nonane

A number of heteroanalogues of bicyclo[3.3.1]nonane containing heteroatoms in 3-, 3,7- and 3,7,9-positions has been synthesized. ¹H NMR measurement has shown that the compounds of the types 4,5 and 6 (Y = oxygen) are double-chairs with the “wings” of the molecule flattened. However, a new conformational effect has been found for the sulfur containing compounds of type 5 and 6 (X,Y = sulfur) which show substantially increased tendency to adopt boat-chair conformations.     

Diels-alder reaction as a synthetic approach to bicyclo[3.3.1]nonane colchicine analogs

Russian Journal of Organic Chemistry -     

Michael reaction on example of unsaturated ketones of bicyclo[3.3.1]nonane series

Conclusions The reaction of bicyclo[3.3.1]-3,7-nonadiene-2,6-dione with nitromethane under the conditions of the Michael reaction in ether solution proceeds with the formation of 2,6-bis(nitromethyl)bicyclo[3.3.1]-nonane-4,8-dione, while in methanol this reaction leads to the formation of a derivative with the bicyclo[2.2.2]octane structure, specifically 3-carbomethoxymethyl-2-nitrobicyclo[2.2.2]-5-octanone.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2624–2626, November, 1981.The authors thank Yu. T. Struchkova, A. I. Akhmedova, and A. I. Yanovskii for running the x-ray structure analysis.     

3-Azabicyclo[3.3.1]nonane Derivatives: IV. Synthesis of Amino Acids with 3-Azabicyclo[3.3.1]nonane Fragment

A series of 1.5-dinitro-3-azabicyclo[3.3.1]non-6-enes was prepared by reduction of 1-R-2,4- and 1-R-3,5-dinitrobenzenes with potassium borohydride followed by Mannich reaction with formaldehyde and amino acids. The molecular structure of (6-bromo-1,5-dinitro-3-azabicyclo[3.3.1]non-6-en-3-yl)acetic acid was studied by X-ray diffraction analysis. The mechanism of decomposition under electron impact was determined for (7-methoxy-1,5-dinitro-3-azabicyclo[3.3.1]non-6-en-3-yl)acetic acid.