F 1,4-Pentadiene

Pentaborane(ll), 0189 Pentacarbonylmanganese hydride, 1808b Pentachloroethane, 0656 Pentacyclo[4.2.0.02,5.03 8.04 7]octane, 2936b f 1,2-Pentadiene, 1889... 

Nickel(II) cyanide, 0993 Nitrogen oxide, 4719 Nitrogen trichloride, 4137 Nitrogen triodide, 4628 Nitrosyl chloride, 4017 Nitryl chloride, 4019 Nitryl hypofluorite, 4298 Oxygen difluoride, 4311 f Pentaborane(9), 0188 f 1,4-Pentadiene, 1891 f 1,3-Pentadiene, 1890 f 1,2-Pentadiene, 1889 f 2-Pentyne, 1893 f 1-Pentyne, 1892... 

A solution of 3-fcrf-butyl-l-(r.6, 6 -trimethylcyclohexen-r-yl)-1.2-pentadien-4-one (52k) (210 mg, 0.806 mmol) in benzene (1.5 mL) is introduced into an ampoule under N2. The solution is cooled to dry ice temperature, and the ampoule is evacuated and then sealed. The ampoule is heated in an oil bath at 68.5 C for 17.5h, then cooled and opened. HPLC purification (Parlisil, 2% F.tOAc/hexanes) gives the trienones in the following order of elution 53k (111.4 mg, 53 %, major diastcrcomcr A. less polar) and 52k (77.2 mg, 37%. minor diastereomer B. more polar) as colorless liquids. The ratio of geometric isomers (Z,Z) Z.F.) is 60 40. The geometric isomers are stable to the thermal conditions described above. 

Pentadiene Heptafluoro-2-trifluoromctliyl- EI0b2. 174 (2,4-Dicnc - 1,3-Diene 1-F - 5-F)... 

The vinylcyclopropane radical cation, generated at 77 K by X-irradiation of (139) in a Freon-113 matrix, was shown to rearrange at 105-110 K to afford two ring-opened distonic radical cationic species.300 The rearrangement reactions of the radical cations of 1,3- and 1,4-pentadiene and cyclopentene and the formation of spin adducts with 2.4.6-tri-/-butylnitrosobenzene (BNB) are discussed. The pulse radiolysis of 1,1 -binaphthyl-2,2,-diyl hydrogenphosphate (BiNPCUH) (140) in deaerated f-butanol at... 

Methyloxobismuthine, see Methylbismuth oxide, 0427 f 2-Methyl-1,3-pentadiene, 2410 f 4-Methyl-1,3-pentadiene, 2411 f 2-Methylpentanal, 2485 f 3-Methylpentanal, 2486 f 2-Methylpentane, see Isohexane, 2527 f 3-Methylpentane, 2528 f 2-Methyl-2-pentanol, 2539 f 2-Methyl-3-pentanone, 2487 f 3-Methyl-2-pentanone, 2488 f 4-Methyl-2-pentanone, 2489a f 2-Methyl-1-pentene, 2456 f 4-Methyl-1-pentene, 2457 f r .v-4-Methyl-2-pentene, 2458 f tra .v-4-Methyl-2-pentene, 2459 3-Methyl-2-penten-4-yn-1 -ol, 2378 Methyl perchlorate, 0435... 

Reaction of polyfluorinated dienes with TFE resembles the reaction of polyfluoropropynes with fluoroethylenes. Polyfluorinated dienes react with TFE at ambient temperature in the presence of SbF5 catalyst [159].F-Heptadiene-2,4 (65) was obtained in 77% yield in reaction of F-pentadiene-1,3 and TFE along with small amounts of F-nonadiene-3,5. F-Hexadiene-2,4 reacts with TFE at 50 °C to give a mixture of isomeric octadienes 66 a, b ... 

Mixed cyclopentadienyl-diene titanium complexes, Cp TiX(diene)(X = Cl, Br, I), have been prepared in 30-60% yield by the stoichiometric reaction of CpTiXs with (2-butene-l,4-diyl)magnesium derivatives or by the reduction of CpTiXs with RMgX (R = i-Pr, f-Bu, Et X = Cl, Br, I) in the presence of conjugated dienes, as shown in Scheme 4. The butadiene, 1,3-pentadiene, and 1,4-diphenylbutadiene complexes of Cp TiX exhibit a unique prone (endo) conformation (13), while the isoprene, 2,3-dimethylbutadiene, and 2,3-diphenylbutadiene complexes prefer the supine (exo) conformation (14). Reduction of Cp TiX(diene) with RMgX or Mg gives a low-valent species, which catalyzes a highly selective (>99%) tail-to-head linear dimerization of isoprene and 2,3-dunethylbutadiene. " ... 

Table 30.2 shows that at/f = 1.599 A the C2 phenyl group in 2-phenyl-1,5-hexadiene provides a net stabilization of = —2.9 kcal/mol, and atR = 2.218 A the Cl and C3 phenyl groups in 1,3-diphenyl-1,5-pentadiene provide a net stabilization of = —2.0 kcal/mol. However, the TS for Cope rearrangement of 1,3,5-triphenyl-1,5-pentadiene occurs with interaUyhc bond lengths of about R = 2.110 A (Table 30.1). At this TS geometry, neither the phenyl groups at Cl and C3 nor the phenyl group C5 provides as much stabilization as these phenyl groups furnish in the TSs for the Cope rearrangements of, respectively, 1,3-diphenyl-1,5-pentadiene at / = 2.218 A and...

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