Hepta-2,5-diene

Bicyclo[2.2.1]hepta-2,5-diene rhodium (I) chloride dimer (norbornadiene rhodium chloride complex dimer) [12257-42-0] M 462, m 240°(dec). Recrystd from hot CHCl3-pet ether as fine crystals soluble in CHCI3 and C H but almost insoluble in Et20 or pet ether. [7 Chem Soc 3178 1959.]... 

Acetic acid, reaction with bicyclo[2.2,1]-hepta-2,5-diene, 45, 74 reaction with dibenzyl ketone, 47, 54... 

Addition, acetic acid to bicyclo[2.2.1]-hepta-2,5-diene to give nortri-cyclyl acetate, 46, 74 1,2,3-benzothiadiazole 1,1-dioxide to cyclopentadiene, 47, 8 benzyne to tetraphenylcyclopentadie-none, 46,107 Br, F to 1-heptene, 46,10 carbon tetrachloride to olefins, 46, 106... 

Bicyclo[2.2.1]hepta-2,5-diene, nitrosyl chloride adduct, 46, 74 reaction with acetic acid to yield nortricyclyl acetate, 46, 74 Bicyclohexyl, 46, 61 Bicyclohexylidene, 47, 34 ejSO-e s-BlCYCLO[3.3.0]OCTANE-2-CAR-BOXYLIC ACID, 47, 10 Bicyclopentadienylidene, octa-chloro-, 46,93... 

A solution of dimethyl 3-acetyl-3-azatetracyclo[3.2.0.02-7.04 6]heptane-l,5-dicarboxylate (2, R1 = Ac R = H), formed by the photolysis (14 h 125-W Hg lamp under N2) of dimethyl 7-acetyl-7-azabicyclo-[2.2.1]hepta-2,5-diene-2,3-dicarboxylate (1 R1 = Ac, R2 = H 1 g, 4mmol) in Et20 (400 mL) at — 40 C, was evaporated to dryness under reduced pressure. The residue (0.7 g, 2.8 mmol) was dissolved in CHC1, and the solution heated under reflux for 1 h. Evaporation of the solvent yielded the crude product which was purified by column chromatography (silica gel, C,H2C12). The yellow fractions were collected and, after removal of the solvent, the residual oil was distilled in a sublimation apparatus to give 3 (R1 = Ac R2 = H) as a yellow oil yield 0.8 g (80%) bp 50 60 C/5 x 10 4 Torr. 

The structure of the product obtained by the silver(I) ion catalyzed ring expansion of anti-1-chloro-2,3-benzo-7-azabicyclo[2.2.l]hepta-2,5-diene, formulated tentatively as 1-methoxy-l/f-1-benzazepine,140 has been shown to be 2-methoxy-6,7-benzo-l-azabicyclo[3.2.0]hept-3-ene... 

Nickel-catalyzed [27t + 27t + 27r] (homo-Diels-Alder) and [27r-i-27r] cycloadditions of bicyclo[2.2.1 ]hepta-2,5-dienes [96]... 

Another versatile two-step synthesis of homobarrelenones [45] is based on the high pressure cycloaddition of tropone (125) and its 2-methoxy-, 2-hydroxy- and 2-chloro-derivatives with 2,3-bis(methoxycarbonyl)-7-oxabicyclo[2.2. l]hepta 2,5-diene (133) followed by thermolysis of the cycloadducts at 130 °C with the... 

Edman and Simmons [146] synthesized bicyclo[2.2.1]hepta-2,5-diene-2,3-dicar-boxylic anhydride 80 as a facially perturbed dienophile on the basis of the norbornadiene motif, and its top selectivity in Diels-Alder reactions with cyclopentadiene (top-exo top-endo = 60 70 1) was observed by Bartlett (Fig. 14) [147], The most preferred addition was top-exo addition, along with the minor addition modes, top-endo bottom-enrfo addition (Fig. 14). The addition of butadiene to this anhydride preferentially afforded the top-adduct (top bottom = 6 1). In the addition of anthracene, a top-adduct was formed exclusively. 

Homoconjugation results in enhanced reactivity of substrates toward ionic hydrogenation. Bicyclo[2.2.1]hepta-2,5-diene forms a mixture of the trifluoroac-etate esters of bicyclo[2.2.1]hepten-2-ol, tricyclo[2.2.1.02 6]heptan-3-ol, and bicyclo[2.2.1]heptan-2-ol in a 62 20 17 ratio on treatment with 10 equivalents of triethylsilane and 20 equivalents of trifluoroacetic acid for 24 hours at room temperature (Eq. 96), 230... 

Every example with a cyclohexene has proved hydrosilation to be very slow and difficult, but this difficulty was not experienced with cyclopen-tene structures by Petrov et al. (27). A number of chlorosilanes were added to bicyclo-(2,2,l)-hept-5-ene, bicyclo-(2,2, l)-hepta-2,5-diene, 2-methyl- and 2-vinylbicyclo-(2,2,l)-hept-5-ene, and dicyclopentadiene under mild conditions. Particularly surprising was the example of Eq. 

Bicyclo[2.2.l]hepta-2,5-diene, irradiation sensitized by acetophenone to give qua-dricyclane, 51, 133 Bicyclo[2.2.0]hexa-2,5-diene,... 

Acetic anhydride, with 2-hep-tanone to give 3-n-butyl-2, 4-pentanedione, 51, 90 ACETIC FORMIC ANHYDRIDE, 50, 1 Acetone azine, 50, 2 ACETONE HYDRAZONE, 50, 2, 28 Acetophenone, 54, 93 as sensitizer for irradiation of bicyclo[2.2.1]hepta-2,5-diene to give quadricyclane,... 

The rate of isomerization of 2-methylbicyclo[2.2. l]hepta-2,5-diene [165] to 5-methylenebicyclo[2.2.1]hept-2-ene [166] by t-BuOK in DMSO (30) was not affected by the presence of 18-crown-6 at low base concentrations (Maskor-nick, 1972). At high concentrations of t-BuOK (>0.1 M), the reaction is zero... 

Azidoacetonitrile, 0714 Azidoacetyl chloride, 0693 4-Azidobenzaldehyde, 2697 7-Azidobicyclo[2.2.l]hepta-2,5-diene, 2777 Azido-2-butyne, 1473... 

The involvement of at least three different forms of the seleniranium ion intermediate, i.e. tight and solvent-separated ion pairs and free ions, has been invoked also to rationalize the different chemical behavior observed in the addition of benzeneselenenyl chloride to bicyclo[2.2.1]hepta-2,5-diene (49) in methanol and in methylene chloride140. As stressed by the authors, the addition of benzeneselenenyl chloride to 49 shows a number of interesting trends. Four products (151-154), all resulting from homoallylic attack, were isolated from the reaction carried out in methanol (equation 131). Furthermore, it... 

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