Reaction of Tricyclo[4.1.0.02,7]heptane with 1-(Arenesulfonyl)-2-phenyldiazenes

Russian Journal of Organic Chemistry - Tricyclo[4.1.0.02,7]heptane reacted with 1-(arenesulfonyl)-2-phenyldiazenes by radical mechanism to give bicyclo[3.1.1]heptane derivatives. Unlike analogous...     

Electronic and Steric Structure of Thermal Isomerization Products of 1-Methyltricyclo[4.1.0.02,7]heptane Radical Cation

Distributions of the positive charge and unpaired electron in stable conformers of the thermal isomerization products of 1-methyltricyclo[4.1.0.02,7]heptane radical cation, having bicyclo[3.1.1]heptane, bicyclo[4.1.0]heptane, bicyclo[3.2.0]hept-6-ene, and 1,3-cycloheptadiene skeletons, were estimated by the PM3 semiempirical method.     

Reactions of Tricyclo[4.1.0.02,7]heptane and 1-Methyltricyclo[4.1.0.02,7]heptane with 2-Bromoethanesulfonyl Bromide

Russian Journal of Organic Chemistry - 2-Bromoethanesulfonyl bromide reacts with tricyclo[4.1.0.02,7]heptane and 1-methyltricyclo[4.1.0.02,7]heptane according to a radical mechanism to give...     

Reaction products of methyl tricyclo[4.1.0.02,7]heptane-1-carboxylate and tricyclo[4.1.0.02,7]hept-1-yl phenyl sulfone with dinitrogen tetraoxide

The reaction of methyl tricyclo[4.1.0.0^2,7]hepatne-1-carboxylate with dinitrogen tetraoxide in diethyl ether at ?10 to 0°C, followed by treatment of the reaction mixture with methanol, gave approximately equal amounts of methyl exo,syn-6,7-dinitro-and exo-6-hydroxy-syn-7-nitrobicyclo[3.1.1]heptane-endo-6-carboxylates. Tricyclo[4.1.0.0^2,7]hept-1-yl phenyl sulfone reacted with dinitrogen tetraoxide under analogous conditions to produce a mixture of diastereoisomeric exo,syn-and endo,syn-6,7-dinitro-6-phenylsulfonylbicyclo-[3.1.1]heptanes and 6,6-dimethoxy-endo-7-nitrobicyclo[3.1.1]heptane at a ratio of 4.5:2:1. Probable factors responsible for the different stereoselectivities in the addition of N₂O₄ at the central C¹-C⁷ bond of the initial tricycloheptane compounds were discussed. The structural parameters of the dinitro ester and related dinitro sulfone were compared on the basis of the X-ray diffraction data.     

Photochemical Selenosulfonation of Tricyclo[4.1.0.02,7]heptane Derivatives

Russian Journal of Organic Chemistry - Se-Phenyl methane-, benzene-, and 4-methylbenzenesulfonoselenoates PhSeSO2R (R = Me, Ph, 4-MeC6H4) react with 1-X-tricyclo[4.1.0.02,7]heptanes (X = Me, Ph,...     

Synthesis of Tricyclo[4.4.0.02,7]decane Derivatives from Tricyclo[4.1.0.02,7]heptane Precursors

Russian Journal of Organic Chemistry - Tricyclo[4.1.0.02,7]heptane and 1-phenyltricyclo[4.1.0.02,7]heptane reacted with 2,3-bis(benzenesulfonyl)propene in boiling toluene (20–24 h) in the...     

Iodination of Tricyclo[4.1.0.02,7]heptane in the Presence of External Nucleophiles

Tricyclo[4.1.0.02,7]heptane reacted with iodine, N-iodosuccinimide, and iodine monochloride in the presence of external nucleophiles yielding products of conjugate endo,syn addition at the central C¹-C⁷ bond. The mechanism of these chemo- and stereoselective reactions is discussed.     

Stereoselective synthesis of substituted bicyclo[3.1.1]heptanes: II.* Synthesis of all diastereoisomers of 7-methyl-and 7-phenylbicyclo[3.1.1]hept-6-yl phenyl sulfones from tricyclo[4.1.0.02,7]heptane precursors

All four possible diastereoisomers of 7-methyl-and 7-phenylbicyclo[3.1.1]hept-6-yl phenyl sulfones were intentionally synthesized from tricyclo[4.1.0.0^2,7]heptane and 1-phenyltricyclo[4.1.0.0^2,7]heptane, respectively. The key stage in the synthesis was regio-and stereoselective cleavage of the central bicyclobutane C¹-C⁷ bond in the tricycloheptane precursors by the action of radical, nucleophilic, and electrophilic reagents. The NMR spectra of the diastereoisomers were compared.     

Nitrochlorination of methyl tricyclo[4.1.0.02,7]heptane-1-carboxylate and phenyl tricyclo[4.1.0.02,7]hept-1-yl sulfone

Treatment of methyl tricyclo[4.1.0.0^2,7]heptane-1-carboxylate and phenyl tricyclo[4.1.0.0^2,7]hept-1-yl sulfone with a ～1:8 mixture of N₂O₄ and NOCl in diethyl ether at ?5 to 0°C gave products of formal anti-addition of NO₂Cl at the central C¹-C⁷ bond. In the reaction with phenyl tricyclo[4.1.0.0^2,7]hept-1-yl sulfone nitryl chloride acts as an effective chlorinating agent; as a result, a mixture of diastereoisomeric syn- and anti-6,7-dichlorobicyclo[3.1.1]hept-6-yl phenyl sulfones at a ratio of 7.5:1 is formed.     

Heterotricyclodecane XI,Sulfoxide und Sulfone von 2-Oxa-7-thia-isotwistan und 2-Oxa-7-thia-twistan sowie Derivaten

The synthesis of sulfoxides and sulfones of 2-oxa-7-thia-isotwistane ( 24 ) and 2-oxa-7-thia-twistane ( 35 ) as well as of several of their derivatives is described. endo-2-Hydroxy-9-thiabicyclo[3.3.1]non-6-ene ( 5 ) was used as starting material. During the course of the reactions special attention was given to intramolecular hydroxy-mercuration and jododemercuration reactions, spectroscopic features, molecular rearrangements and stereospecificity of oxidations of sulfides to sulfoxides.     

Adducts of Tricyclo[4.1.0.0<Superscript>2,7</Superscript>]heptane hydrocarbons with methane- and Halomethanesulfonyl Thiocyanates and their transformations in the presence of bases (nucleophiles)

1-R-Tricyclo[4.1.0.0^2,7]heptanes (R = H, Me, Ph) take up methane- and halomethanesulfonyl thiocyanates XCH₂SO₂SCN (X = H, Cl, Br) at the central C¹–C⁷ bond in benzene at 20°C with high anti-selectivity to give bicyclo[3.1.1]heptane derivatives with the 7-endo-oriented sulfonyl group and the thiocyanato group in the geminal position with respect to the R substituent. The syn-adducts lose HSCN molecule by the action of potassium tert-butoxide in THF at 0°C or on heating in boiling aqueous dioxane containing NaOH with formation of 1-(X-methylsulfonyl)tricyclo[4.1.0.0^2,7]heptanes. Under analogous conditions the anti-adducts (X = Me) are converted into 1,2-bis(7-syn-methylsulfonyl-6-endo-R-bicyclo[3.1.1]hept-6-exo-yl)disulfanes. The anti-adduct derived from unsubstituted tricyclo[4.1.0.0^2,7]heptane and MeSO₂SCN reacted with methyllithium or phenylmagnesium bromide to produce 7-anti-methyl(phenyl)sulfanyl-6-endo-methylsulfonylbicyclo-[3.1.1]heptanes which were also obtained by photochemical addition of MeSO₂SMe(or Ph) to tricyclo-[4.1.0.0^2,7]heptane. Geometric parameters of radical intermediates in the sulfonylation of 1-R-tricyclo-[4.1.0.0^2,7]heptanes were optimized ab initio using 6-31G basis set.     

Products of reaction of 1-phenyltricyclo[4.1.0.02,7]heptane with N-iodosuccinimide in aqueous THF

Russian Journal of Organic Chemistry - Iodohydroxylation of 1-phenyltricyclo[4.1.0.02,7]heptane in aqueous THF at 20°C with N-iodosuccinimide proceeds at the central bicyclobutane bond C 1...     

The Circular Dichroism of 5,6-Dimethylidene-2-bicyclo[2.2.n]alky Esters. Chiral Exciton Coupling between Benzoate and Exocyclic s-cis-Butadiene Chromophores

The optically pure aryl-substituted 5,6-dimethylidene-2-bicyclo[2.2.1]heptyl benzoates 12–21 were prepared; their UV absorption and CD spectra are reported. The (?)-(1S,2S)-esters 17–21 with carbonyl groups in endo-position exhibit typical excitonsplit Cotton effects whereas the corresponding (?)-(1S,2R)-esters 12 - 16 with carbonyl groups in exo-position do not present such effects. The chiral exciton coupling between the exocyclic diene and a remote p-substituted benzoate chromophore can be used for unambiguous assignment of the absolute configuration of 5,6-dimethylidene-2-endo-bicyclo[2.2.1]heptyl derivatives. The method is applied to establish the absolute configuration of 5,6-dimethylidene-2-exo and -2-endo-bicyclo[2.2.2.]octyl p-bromobenzoates (?)- 24 and (?)- 25 .     

Face Selectivity of the Diels-Alder Additions of 2-Substituted 5,6-bis((E)-chloromethylidene)bicyclo[2.2.2]octanes

The preparation of 5,6-bis((E)-chlorommethylidene)bicyclo[2.2.2]oct-2-ene ( 13 ), 2,3-bis((E)-chloromethyl idene)-5exo,6exo- and -5endo,6endo-epoxybicyclo[2.2.2] octane ( 14 and 15 ), 5,6-bis((E)-chloromethylidene)-2exo- and -2endo-bicyclo[2.2.2] octanol ( 16 and 17 ) and 5,6-bis((E)-chloromethylidene)-2-bicyclo[2.2.2]octanone ( 18 ) are described. The face selectivity (endo-face vs. exo-face attack onto the exo-cyclic diene) of their cycloadditions to tetracyanoethylene has been determined in benzene at 20°. It is 78/22, 80/20, 60/40, 68/32, 3/97 and 30/70 for 13 , 14 , 15 , 16 , 17 and 18 , respectively.     

Synthesis of the 1-Bromotricyclo[4.1.0.02,7]heptane Adduct with 2-Bromoethanesulfonyl Bromide and Its Transformations

Russian Journal of Organic Chemistry - The addition of 2-bromoethanesulfonyl bromide to 1-bromotricyclo[4.1.0.02,7]heptane at the C1–C7 central bicyclobutane bond follows a radical mechanism...     

Synthesis and isomerization of epoxides derived from 7-phenylsulfonyl-and 7-methylsulfonyl-6-methylidenebicyclo[3.1.1]heptanes

Oxidation of exo-7-phenylsulfonyl-and exo-7-methylsulfonyl-6-methylidenebicyclo[3.1.1]heptanes with m-chloroperoxybenzoic acid gave the corresponding epoxy derivatives, anti-7-phenylsulfonyl-and anti-7-methylsulfonyl-endo-2′-oxaspiro[bicyclo[3.1.1]heptane-6,2′-cyclopropanes]. Treatment of the phenylsulfonyl-substituted epoxide with potassium tert-butoxide in THF led to the 1,3-cyclization product, 7-phenylsulfonyltricyclo[4.1.0.0^2,7]hept-1-ylmethanol. anti-7-Methylsulfonyl-endo-2′-oxaspiro[bicyclo[3.1.1]heptane-6,2′-cyclopropane] under analogous conditions underwent 1,6-cyclization, being converted into 6-hydroxy-3λ⁶-thiatricyclo[4.4.0.0^2,7]decane 3,3-dioxide.     

The synthesis of some derivatives of benzo[f]naphtho[1,8-bc]thiepin-12-one

The preparations of benzo[f]naphtho[1,8-bc]thiepin-12-one, its 6-methyl and 6-methoxy derivatives and their corresponding sulfoxides and sulfones are described. They involve the coupling of suitable halogen naphthyl derivatives with thiophenoxides with the help of copper and the cyclization of the resulting acids with phosphorus pentoxide in benzene. The oxidations to sulfoxides and sulfones were performed with iodo-benzene diacetate and hydrogen peroxide, respectively. The ir and pmr spectra are reported.     

Vibrational circular dichroism DFT study on bicyclo[3.3.0]octane derivatives

The absolute configurations of four bicylco[3.3.0]octane derivatives: endo-bicyclo[3.3.0]octane-2,6-diol, endo-2,6-diacetoxybicyclo[3.3.0]octane, endo-bicyclo[3.3.0]octane-2,6-dione and bicyclo[3.3.0]octa-2,6-dien-2,6-bistriflate were studied by vibrational circular dichroism (VCD). These chiral derivates are of interest as intermediates in the asymmetric synthesis of enantiomerically pure natural products and chiral ligands for asymmetric catalysis. VCD has been used to determine the absolute configuration of each compound, proving the capability of VCD for molecules with several stereogenic centres. IR and VCD spectra have been simulated at the B3LYP/6-31G¹ level for all possible diastereomers. Based on the agreement between the experimental and the calculated spectrum, the stereochemistry of each compound could be assigned. The predicted absolute configurations are found to agree with literature data.     

Exo- und endo-Tricarbonyleisenkomplexe von bicyclischen 2,3-Dimethylidenverbindungen

Exo- and endo-Tricarbonyliron Complexes of Bicyclic 2,3-Dimethylidene Compounds. The preparation of exo- and endo-tricarbonyliron complexes (exo- and endo- 5 , -6 , -8 , and 9 ) of 2,3-dimethylidene-5-bicyclo[2.2.1]heptene( 1 ), -bicyclo[2.2.1]-heptane ( 2 ), -5-bicyclo[2.2.2]octene ( 3 ) and -bicyclo[2.2.2]octane ( 4 ) is described. The complexes are obtained by thermal reaction of the bicyclic butadienes with di-ironenneacarbonyl in hexane solution. exo- and endo- 5 are also formed photochemically from ironpentacarbonyl and 1 in pentane solution at ?35°. The structural assignment of exo- and endo -5 and -6 is based on their mass-spectra and on coordination shifts in ¹H- and ¹³C-NMR.-spectra exo- and endo -6 are correlated with exo- and endo -5 , respectively, by hydrogenation. Hydrogenation of the uncomplexed double bond in exo- and endo -5 occurs in both complexes from the exo side as shown by deuteration experiments. The free ligand 1 reacts in the same stereospecific manner.     

Synthesis of 7-sulfonyl-substituted norpinan-6-ones and -thiones from 1-bromotricyclo[4.1.0.0<Superscript>2,7</Superscript>]heptane

1-Bromotricyclo[4.1.0.0^2,7]heptane reacted with benzene- and methanesulfonyl thiocyanates in benzene at 20°C via anti addition to the central C¹–C⁷ bicyclobutane bond with formation of 6-endo-bromo-6-exo-thiocyanato-7-syn-(R-sulfonyl)bicyclo[3.1.1]heptanes. Treatment of the benzenesulfonyl thiocyanate adduct with potassium tert-butoxide in THF at 20°C gave 7-endo-(benzenesulfonyl)norpinan-6-one, whereas the reaction with 1,8-diazabicyclo[5.4.0]undec-7-ene in methylene chloride afforded 7-exo-(benzenesulfonyl)-norpinane-6-thione which was converted into 7-exo-(benzenesulfonyl)norpinan-6-one by alkaline hydrolysis.