Syntheses of di-, tri-, and tetra-cyclopropylethylenes

Teraji, Tsutomu; Moritani, Ichiro; Tsuda, Emako; Nishida, Shuzo

doi:10.1039/j39710003252

Cited by 21 publications

(21 citation statements)

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“…20 Condensation of the diol 18 with benzaldehyde (Scheme 3) gave the benzylidene derivative 20 (64%) which was subsequently lithiated with n-butyllithium to provide geometrically pure (E)alkene 9 (60%) on cycloreversion of lithium benzoate. Nishida and co-workers previously reported a geometrically nonselective syntheses of both (E)-and (Z)-1,2-di-(cyclopropyl)ethene, 21 and comparisons of their spectroscopic data with the corresponding data we observed for alkene 9 are fully consistent with the assignment of trans-geometry.…”

Section: Resultssupporting

confidence: 81%

Stereochemical Elucidation of the Pentacyclopropane Antifungal Agent FR-900848

et al. 1996

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Full structural elucidation of FR-900848, an antifungal pentacyclopropane nucleoside natural product from Streptoverticillium fervens, is reported. A series of model compounds were prepared using multiple asymmetric Simmons−Smith cyclopropanation reactions. Comparisons of spectroscopic data of synthetic alkenes 9 and 10, quatercyclopropanes 11 and 12, and imidazolidines 13 and 14 with FR-900848 and its degradation products 2, 3, and 4 were consistent with the full structural assignment of the natural product as structure 7.

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Section: Resultssupporting

confidence: 81%

Stereochemical Elucidation of the Pentacyclopropane Antifungal Agent FR-900848

et al. 1996

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“…Diphenyl diselenide and diphenyl ditelluride were prepared according to the literature, and were recrystallized from hexane. Vinylcyclopropanes were synthesized according to the literature . Unless otherwise noted, acetylenes and olefins were used commercially and were purified by distillation or recrystallization.…”

Section: Methodsmentioning

confidence: 99%

Highly Selective Thioselenation of Vinylcyclopropanes with a (PhS)₂−(PhSe)₂ Binary System and Its Application to Thiotelluration

Ogawa

Obayashi

et al. 1998

J. Org. Chem.

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A novel, highly selective method for introducing organic sulfur, selenium, and tellurium functions into vinylic cyclopropanes has been developed on the basis of the relative reactivities of organic dichalcogenides and chalcogen-centered radicals. Upon irradiation with the light of wavelength over 300 nm, the reaction of vinylcyclopropanes with diphenyl disulfide and diphenyl diselenide proceeds smoothly to provide the corresponding gamma-(selenoethyl)allylic sulfides regioselectively in good yields. Similarly, vinylcyclopropanes undergo regioselective thiotelluration by use of a novel (PhS)(2)-(PhTe)(2) binary system, affording the corresponding ring-opened thiotelluration product in good yields. Furthermore, the scope and limitations of this (PhS)(2)-(PhTe)(2) binary system are discussed.

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“…2-Cyclopropylpropene, 7, was prepared in 98% yield from cyclopropyl methyl ketone according to a literature procedure . Liquid, 1 H-NMR (250 MHz, CDCl 3 ) 0.35 (m, 2H), 0.55 (m, 2H), 1.29 (m, 1H), 1.53 (s, 3H), 4.55 (d, 1H, J = 0.2 Hz), 4.62 (d, 1H, J = 0.2 Hz) in good agreement with the literature …”

Section: Methodsmentioning

confidence: 85%

Clocking Tertiary Cyclopropylcarbinyl Radical Rearrangements¹

Engel

Banks

et al. 1997

J. Org. Chem.

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Three independent methods have been employed to estimate the rate constant, k 1 , for ring-opening of the 2-cyclopropyl-2-propyl radical, 1, at room temperature. These three estimates are based on chemical trapping of 1 and the ring-opened 4-methylpent-3-ene-1-yl radical by thiophenol (k 1 ) (1.6 5 ( 0.4 1 ) × 10 7 M -1 s -1 ), 9-azabicyclo[3.3.1]nonane-N-oxyl (k 1 ) (1.7 6 ( 0.3 4 ) × 10 7 M -1 s -1 ) and 2,2,6,6-tetramethylpiperidine-N-oxyl (k 1 ) (2.1 ( 0.4) × 10 7 M -1 s -1 ) and absolute rate constants for nonrearranging radicals structurally related to 1. The mean value for k 1 ((1.8 4 ( 0.4) × 10 7 M -1 s -1 ) should be used when 1 is employed as a tertiary alkyl free radical clock at ambient temperatures.Radicals which undergo unimolecular rearrangements have been described as "free radical clocks". 3 Provided the rate constant, k r , for conversion of the unrearranged radical, U • , to the rearranged radical, R • , is known (i.e., provided the clock has been calibrated) 3,4 the rate constant, k T , for any competing reaction involving U • can be calculated by determining the relative yields of the U • and R • derived products, e.g.,

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Syntheses of di-, tri-, and tetra-cyclopropylethylenes

Cited by 21 publications

References 0 publications

Stereochemical Elucidation of the Pentacyclopropane Antifungal Agent FR-900848

Stereochemical Elucidation of the Pentacyclopropane Antifungal Agent FR-900848

Highly Selective Thioselenation of Vinylcyclopropanes with a (PhS)₂−(PhSe)₂ Binary System and Its Application to Thiotelluration

Clocking Tertiary Cyclopropylcarbinyl Radical Rearrangements¹

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Syntheses of di-, tri-, and tetra-cyclopropylethylenes

Cited by 21 publications

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Stereochemical Elucidation of the Pentacyclopropane Antifungal Agent FR-900848

Stereochemical Elucidation of the Pentacyclopropane Antifungal Agent FR-900848

Highly Selective Thioselenation of Vinylcyclopropanes with a (PhS)2−(PhSe)2 Binary System and Its Application to Thiotelluration

Clocking Tertiary Cyclopropylcarbinyl Radical Rearrangements1

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Highly Selective Thioselenation of Vinylcyclopropanes with a (PhS)₂−(PhSe)₂ Binary System and Its Application to Thiotelluration

Clocking Tertiary Cyclopropylcarbinyl Radical Rearrangements¹