Alkylations of tricyclo[5.2.1.0]deca-4,8-dien-3-one by a cuprate reaction

Alkylation at C₆ of tricyclo[5.2.1.0^2,6]deca-4,8-dien-3-one (R=H) was achieved by treatment of 6-bromotricyclo[5.2.1.0^2,6]deca-4,8-dien-3-one with lithium dimethylcuprate and subsequently with an appropriate electrophile. The best results were obtained in THF as the solvent. A wide range of alkyl halides, bromo ketones and esters, and acetyl chloride resulted in C₆-tricyclo[5.2.1.0^2,6]deca-4,8-dien-3-ones in moderate to good yields. This alkylation reaction proceeds via a C₆-carbanionic Cu intermediate, which is likely stabilized by the enone olefinic bond. 6-Bromo-endo-tricyclo[5.2.1.0^2,6]dec-8-en-3-one, which lacks this double bond, behaves differently. Treatment with lithium dimethylcuprate leads to dehydrobromination to give tricyclo[5.2.1.0^2,6]deca-2(6),8-dien-3-one in high yield.     

Reaction of mercury salts with dimethyl tricyclo [4.2.2.02,5]deca-3,7-diene-cis-endo-9,10-dicarboxylate in acetic acid

The reaction of dimethyl tricyclo[4.2.2.0^2,5]deca-3,7-diene-cis-endo-9,10-dicarboxylate with mercury salts Hg(OCOR)₂ (R=CCl₃, CF₃, CH₂Cl) in acetic acid yields a mixture of solvoadducts and products of addition of the anionic moiety of the reagent having thetrans-configuration. In the case of Hg(OCOCCl₃)₂,cis-solvoadduct was detected along with thetrans-isomer. The amount of the addition products is determined by the nature of the mercury salt and increases in the order Hg(OCOCH₂Cl)₂<Hg(OCOCCl₃)₂=Hg(OCOCF₃)₂. The reaction is assumed to involve contact and solvent-separated ion pairs. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2173–2176, November, 1999.     

Photochemistry of tricyclo [4.2.2.02,5] deca-3,7-dien-9-one: a source of many interesting polycycles

New syntheses of tricyclo [4.2.2.0^2,5] deca-3,7-dien-9-one are described. Direct and sensitised photolysis of this ring system provides facile entry to several novel polycyclics.     

Facial selectivity in addition reactions to the highly strained enone in tricyclo[5.2.1.0]deca-2(6),8-dienone and tricyclo[5.2.1.0]dec-2(6)-enone

Tricyclo[5.2.1.0^2,6]deca-2(6),8-dien-3-one contains a highly strained central double bond due to geometrical constraints imposed by the tricyclic skeleton which does not allow optimal sp² hybridization at the C₂ and C₆ bridgehead positions. Michael addition of various nucleophiles (alkoxides, cyanide, and malonate) under protic conditions resulted in an exclusive exo-facial selectivity. This preference can be explained by steric and electronic factors. Michael additions using lithium dialkylcuprates resulted in predominant formation of endo-products, but also some exo-products were obtained. These exo-products arising from endo-approach may be the result of coordination of the cuprate with both the enone moiety and the olefinic C₈-C₉ bond. Michael additions to tricyclo[5.2.1.0^2,6]dec-2(6)-en-3-one, which lacks this C₈-C₉ double bond showed exclusive exo-facial selectivity to give exo-products. Besides these additions were all considerably slower than those to tricyclo[5.2.1.0^2,6]deca-2(6),8-dien-3-one proving significant electronic participation of the C₈-C₉ double bond in reactions with this substrate.     

Tetracyclo[5.3.0.02,803,6]deca-4,9-diene. A new (CH)10 hydrocarbon

Irradiation of tricyclo[5.3.0.0^2,8]deca-3,5-dien-9-one ethylene acetal yields tetracyclo[5.3.0.0^2,80^3,6]dec-4-en-9-one ethylene acetal as main product which can be converted to the title compound, a new (CH)¹⁰ hydrocarbon.     

Novel skeletal rearrangement in addition reaction to tricyclo[4,2,2,02,5]deca-3,7-diene system

The “doping-addition” of RSCl to the tricyclo[4,2,2,0^2,5]deca-3,7-diene derivatives which are incapable of lactone ring closure proceeds to give the novel type of rearranged product, $\text{7}$, due to the two subsequent 1,2-shifts.     

Cyclopropanation and epoxidation of tricyclo[5.2.1.0]deca-2(6),8-dien-3-one

Cyclopropanation of tricyclo[5.2.1.0^2,6]deca-2(6),8-dien-3-one using dimethylsulfoxonium ylide gave a highly strained annulated cyclopropane in 68% yield with complete exo-face selectivity. Nucleophilic epoxidation gave a strained epoxide in 68% yield, again completely exo-face selective. Surprisingly, using methanol as the co-solvent in this epoxidation yielded a disubstituted tricyclodecenone in 85% yield instead of the epoxide. This result can be explained by a Payne-type rearrangement of the initially formed epoxide.     

The Adamantane Rearrangement of Tricyclo[4.2.2.01,5]decane to Tricyclo[5.3.0.04,8]decane

Regioselective generation of the C(2)-carbocation a of tricyclo[4.2.2.0^1,5]decane ( 1 ) by treatment of both corresponding epimeric alcohols 5 and 6 with BF₃ and trapping the rearranged tricyclo[5.3.0.0^4,8]decan-7-yl carbocation b with Et₃SiH as hydride-ion donor (ionic hydrogenation) gives the corresponding hydrocarbon 3 as sole product in almost quantitative yield. The latter is a known intermediate in the Lewis-acid-catalyzed rearrangement of 1 to adamantane ( 4 ).     

New systems for classical nitrosohalogenation of alkenes 1. Reactions of alkenes with ethyl nitrite in the presence of phosphorus halides and thionyl chloride

Studies of nitrosation of norbornene and norbornadiene derivatives and dimethyl tricyclo[4.2.2.0^2,5]deca-3,7-diene-9,10-cis-endo-dicarboxylate demonstrated that nitrosation of alkenes with EtONO-PHal₃, EtONO-POHal₃ (Hal = Cl or Br), and EtONO-SOCl₂ systems can afford nitroso halides in high yields without the formation of by-products (ketones and oximes). The reactions with 5-substituted norbornenes are nonregioselective. The trans dimer of endo-5-trifluoromethyl-cis-exo-2-chloro-3-nitrosobicyclo[2.2.1]heptane was studied by X-ray diffraction. Dedicated to Academician N. S. Zefirov on the occasion of his 70th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2070–2080, September, 2005.     

Trifluoromethyl substituted ring systems: synthesis,and reactivity towards metal carbonyls

Hexafluoro-but-2-yne and actafluoro-but-2-ene both readily add to cyclopentadiene. Similar Diels-Alder reactions occur between hexafluoro-but-2-yne and cycloheptatriene and cyclooctatetraene. 2,3-Bis(trifluoromethyl)bicyclo[2.2.1]hepta-2,5-diene reacts with chromium and molybdenum hexacarbonyls, and with enneacarbonyl di-iron to give metal complexes [M(diene)(CO)₄] (M = Cr, Mo) and [Fe(diene)(CO)₃], respectively. 6,7-Bis-(trifluoromethyl)tricyclo[3.2.2.0^2,4]nona-6,8-diene obtained from hexafluoro-but-2-yne and cycloheptatriene and 7,8-bis(trifluoromethyl)tricyclo[4.2.2.0^2,5]deca-3,7,9-triene formed from hexafluoro-but-2-yne and cyclooctatetraene also react with molybdenum hexacarbonyl to form complexes of molybdenum di- and tetracarbonyl groups, respectively. ¹H, ¹⁹F and ¹³C n.m.r. spectra of the compounds are described.     

The Synthesis of 4,7-Bis(dialkylamino)tricyclo[5.2.1.04,10]deca-1(10),2,5,8-tetraenes and their Reduction with Alkali Metal

The synthesis and characterization of the novel 4,7-bis(dialkylamino)tricyclo[5.2.1.0^4,10]deca-1(10), 2,5,8-tetraenes 12 from 1,4,7-trihalotriquinacenes 8 and secondary amines is reported. The structural and electronic characteristics of these as well as the acepentalene dianion ( 3^2? ) and some related systems as determined by semiempirical (MNDO) calculations are discussed. Thereby, 3^2? should be a triply etheno-bridged trimethylenemethane dianion exhibiting Y-delocalization favored over the formation of a peripheral 10π-electronic system. Attempts directed towards the generation of 3^2? by reacting tetraenes 12 with Na led to the formation of tris(dialkylamino)triquinacenes 9 , presumably by a kind of reduction/disproportionation mechanism.     

Doping-addition of arylsulfenyl chlorides to the tricyclo[4,2,2,02,5]deca-3,7,9-triene system: skeletal rearrangements and serendipitious products

“doping-addition” of 2-NO₂C₆H₄SCl to the tricyclo[4,2,2,0^2,5]deca-3,7,9-triene system

occurs to give unusual products: (i) rearranged caged cyclopropane

and (ii) the stable cross-perchlorate

.     

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.     

Stereospecific syn-addition of iodine azide to strained cyclobutene moeity

Addition of tricyclo[4.2.2.0^2.5]deca-3,7-diene and iodine azide was found to be syn on the cyclobutene moiety. Structure determination of the adducts and the formation mechanism are discussed.     

Density functional study of tricyclo[3,3,1,13,7]decane and tricyclo[3,3,1,13,7]decsilane and their halogen derivatives

The B3LYP/3‐21G* ab initio molecular orbital method from the Gaussian 94 computer program package was applied to study tricyclo[3,3,1,1^3,7]decane and tricyclo[3,3,1,1^3,7]decsilane molecules and their halogen derivatives (1,3,5,7‐tetrahalotricyclo[3,3,1,1^3,7]decane and 1,3,5,7‐tetrahalotricyclo[3,3,1,1^3,7]decsilane, C₁₀H₁₂X₄, and Si₁₀H₁₂X₄). The optimized structures of these compounds were obtained. Ionization potentials, HOMO and LUMO energies, energy gaps, heats of formation, atomization energies, and vibration frequencies were calculated. These calculations indicate that these molecules are stable and have T_d symmetry. Tricyclo[3,3,1,1^3,7]decsilane and its halogen derivatives (Si₁₀H₁₂X₄) are found to have higher conductivity than that of tricyclo[3,3,1,1^3,7]decane and its halogen derivatives (C₁₀H₁₂X₄). 1,3,5,7‐Tetraflourotricyclo[3,3,1,1^3,7]decane (C₁₀H₁₂F₄) and 1,3,5,7‐tetraflourotricyclo[3,3,1,1^3,7]decsilane (Si₁₀H₁₂F₄) were found to be the easiest compounds to form and the most difficult to dissociate of all 1,3,5,7‐tetrahalotricyclo[3,3,1,1^3,7]decane and 1,3,5,7‐tetrahalotricyclo[3,3,1,1^3,7]decsilane compounds, respectively. ©1999 John Wiley & Sons, Inc. Int J Quant Chem 72: 189–198, 1999     

Addition of dichlorocarbene to tricyclo[4.3.0.03,7]nona-4,8-diene

Addition of dichlorocarbene to tricyclo[4.3.0.0^3,7]nona-4,8-diene (brexadiene) under conditions of phase transfer catalysis occurs from theexo side. Cyclopropyl-allyl rearrangement of intermediate chlorocyclopropanes yields tricyclo[5.4.0.0^3,8]undecadienes. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1494–1497, August, 1997.     

Stereochemistry of the complexation of derivatives of tricyclo[4.2.2.05,8] decadiene and related cycloalkenes with AgEu(fod)4

The stereochemical features of the complexation of derivatives of tricyclo[4.2.2.0^{5, 8}]decadiene and related cycloalkenes with AgEu (fod)₄ have been investigated by PMR spectroscopy with silver-lanthanide shift reagents. The bidentate structure of the complexes investigated has been established on the basis of the results of calculations carried out with the use of silver—lanthanide-induced shifts.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 21, No. 6, pp. 736–739, November–December, 1985.We express our thanks to A. S. Koz'min and V. N. Kirin for supplying the samples of compounds 1 and 2.     

Cobalt(I)-catalyzed [4π+2π] cycloaddition reactions of 1,3-diynes with 1,3,5-cyclooctatriene

The cycloaddition reaction between conjugated diynes and 1,3,5-cyclooctatriene in the presence of the catalyst Co(acac)₂/dppe/Zn/ZnI₂, led to the selective formation of tricyclo[4.2.2.0^2,5]deca-7,9-diene derivatives in 72–85% yield.     

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.     

Nucleophilic Addition to C,C-Double Bonds. Part VIII. The standard enthalpies of formation of anti9,10-10endo-hydroxytricyclo [4.2.1.12,5]deca-3,7-dien-9-one and 9-Oxatetracyclo [5.4.0.03,10.04,8]undec-5-en-2-one and kinetic data for the cyclization of the olefinic alcohol to the ether

In view of the significance of steric compression in the base-catalyzed intramolecular cyclization of polycyclic olefinic alcohols, the standard enthalpies of formation of anti^9,10-10 endo-hydroxytricyclo [4.2.1.1^2,5]deca-3,7-dien-9-one (1) and 9-oxatetracyclo [5.4.0.0^3,10.0^4,8]undec-5-en-2-one (2) as well as the kinetics of the ether formation 1 → 2 were determined.