Oxidationsreaktionen am Benzvalen: Ozonolyse,cis-Hydroxylierung, Epoxidation und Singulettsauerstoff-Addition

Leininger, Hartmut; Christl, Manfred

doi:10.1002/ange.19800920610

Cited by 11 publications

(8 citation statements)

References 14 publications

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“…Earlier attempts to epoxidize bullvalene with buffered mchloroperbenzoic acid, as successfully applied for the epoxi-dation of barrelene 3, [11] and even with the milder N-benzoylpercarbamidic acid (PhCN, H 2 O 2 ), which had successfully been used for the epoxidation of benzvalene, [13] only led to decomposition or at best to the rearrangement product rac-8. Apparently, bullvalene trisepoxide rac-6 is even more sensitive towards acid than barrelene trisepoxide 4 d. Eventually, the racemic trisepoxide rac-6 was obtained in virtually quantitative yield by treatment of 1 with a buffered solution of Oxone in a mixture of acetone, dichloromethane and water.…”

Section: Resultsmentioning

confidence: 99%

“…Upon treatment with boron trifluoride etherate at À78 8C, trisepoxide rac-6 rearranged with retention of the skeletal three-membered carbocycle to give the hexacyclic trisether rac-8 in virtually quantitative yield (Scheme 3). -4,8,12-trioxahexacyclo[4.4.3.0 3,5 0 7,9 0 2,10 0 11,13 ]tridecane (trisepoxide rac-6) in the crystal. [16] However, the same quantitative rearrangement to rac-8 was observed upon simply stirring a solution of rac-6 in dichloromethane with anhydrous magnesium sulfate at ambient temperature for 15 min.…”

Section: Resultsmentioning

confidence: 99%

“…J. 2005, 11, 2012 -2018 www.chemeurj.org 4,8,.0 3,5 0 7,9 0 2,10 0 11,13 ]tridecane (bullvalene trisepoxide, rac-6): a) To a vigorously stirred solution of bullvalene (1) [35] (1.20 g, 9.22 mmol) in a mixture of acetone (35 mL) and dichloromethane (20 mL) was added a neutralized solution of Oxone [prepared from 2 KHSO 5 ·KHSO 4 ·K 2 SO 4 (Oxone, 28.29 g, 92.0 mmol SO 5 2À ), NaHCO 3 (11.59 g, 138.0 mmol) in H 2 O (150 mL)] [36] at 0 8C over a period of 10 min. After stirring at ambient temp.…”

Section: Methodsmentioning

confidence: 99%

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Bullvalene Trisepoxide and Its Stereospecific Rearrangement to 2,8,12‐Trioxahexacyclo[8.3.0.0^3,90^4,60^5,130^7,11]tridecane: Two New C₃‐Symmetrical Oligocycles with Propeller Chirality

Liang

Lee

Kozhushkov

et al. 2005

Chemistry A European J

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Epoxidation of bullvalene (1) with a neutralized solution of Oxone gave racemic trisepoxide rac-6 in 93 % isolated yield. Its structure was examined by X-ray crystallography. The two enantiomers of 6 were separated by preparative HPLC and exhibited specific rotations of [alpha](25)(D)= +160, [alpha](25)(365)= +567 (c=0.946, CHCl(3)) for the firstly eluted and [alpha](25)(D)= -157, [alpha](25)(365)= -554 (c=0.986, CHCl3) for the secondly eluted enantiomer of 6. The geometry of (+)-6 and the absolute configuration of (-)-6 were determined by X-ray crystal structure analysis and anomalous diffraction, respectively. According to this, (-)-6 possesses (3R,5S,7S,9R,11R,13S)- and (+)-6 has (3S,5R,7R,9S,11S,13R)-configuration. Upon treatment with BF(3)Et(2)O at -78 degrees C, trisepoxide rac-6 rearranges with retention of the skeletal three-membered carbocycle to give the cage trisether rac-8, as proved by X-ray crystal structure analysis, in virtually quantitative yield. Enantiomers of rac-8 were separated by preparative HPLC and exhibited specific rotations of [alpha](25)(D)= +49, [alpha](25)(365)= +170 (c=1.01, CHCl3) (firstly eluting) and [alpha](25)(D)= -46, [alpha](25)(365)= -160 (c=1.02, CHCl(3)) (secondly eluting enantiomer). The absolute configuration of (-)-8 was determined by anomalous diffraction to be (1R,3R,7R,9R,11R,13R). DFT computations at the TD-B3 LYP/6-31+G(d,p)//B3 LYP/6-31+G(d) level of theory for (3R,5S,7S,9R,11R,13S)-6 and (1R,3R,7R,9R,11R,13R)-8 predicted specific rotations of -206.7 and -83.4, respectively. Acid-catalyzed isomerization of the enantiomerically pure (+)-6 proceeded without racemization to give exclusively (-)-8, and (-)-6 provided only (+)-8. Thus, this isomerization occurs with ring opening of the three C--O bonds in the epoxide moieties in the alpha-position relative to the three-membered carbocycle rather than in the beta-position.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Bullvalene Trisepoxide and Its Stereospecific Rearrangement to 2,8,12‐Trioxahexacyclo[8.3.0.0^3,90^4,60^5,130^7,11]tridecane: Two New C₃‐Symmetrical Oligocycles with Propeller Chirality

Liang

Lee

Kozhushkov

et al. 2005

Chemistry A European J

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“…aluminum hydride (-30°C) afforded a bicyclic diol 178 which by treating with the same reagent was converted into optically pure diol 179 [87] (Scheme 37).…”

Section: Transformations Of Peroxide Products Of Olefins Ozonolysismentioning

confidence: 99%

Transformations of peroxide products of olefins ozonolysis

et al. 2010

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“…Die Doppelbindung von (1) kann nicht mit katalytisch aktiviertem Wasserstoff hydriert werdcn, da unter den Bedin· gungen dieser Umsetzung Dihydrobenzvalen (2) zum Me· thylcyclopentan (78) Auch die Umwandlungen von (105) in (128)1 4 ]oct-7.en um lS8 ).…”

Section: Hydrierung Mit Diimin Und Cis-hydroxylierungunclassified

Benzvalen – Eigenschaften und Synthesepotential

Christl¹

1981

Angewandte Chemie

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Naehdem bereits die substituierten Derivate (243) Spektroskopie des BenzvaleosBenzvalen (1) enthlilt zwei "funktionelle Gruppen" -die olefinische Doppelbindung und das Bicyclo(1.1.0]butan-System -in enger Nachbarschaft, was zu starker Wechselwirkung zwischen diesen Strukturelementen fiihrt. Das iluBert sich im UV -Spektrum mit einer strukturierten Bande, deren Hauptmaximum bei A= 217 nm (e«:J 2500) liegt(a); 1,2-Dialkylethene und Bicyclo(l.1.0jbutan(9) weisen hingegen oberhalb 200 run keine signifikante Absorption aut: Mindestens zum Tell geht diesc verhliltnismi.6ig Jangwellige Bande auf die Anhebung der Energie des 'IT-Orbitals der Doppelbindung (4b 2 ) durch Wechselwirkung mit einem besetzten Orbital geeigneter Symmetrie des Bicyclo[1.1.0)butan-Systems zuriick; dies foIgt aus dem Photoelektronenspektrum mit dem ersten Ionisationspotcntial bei 8.55 eV(IG-12 1 (Cyclopenten 9.01,9.18 eV["·), Norbomen 8.97 eV(l3b). Schema 1 zeigt die drei obersten besetzten Orbitale von (1). Die Zuordnung beruht auf Rechnungen)6,10), nach denen die zweite Bande bei 9,75 eV zum Orbital gehort, das nahezu ausschlieBlich in der zentralen Bicyclo(1. (1) sind genau analysiert worden. Die mit 1556 cm -I ungewohnlich niedrige Frequenz der C=C-Streckschwingung deutet -ebenso wie die NMR-Spektren (Schema 2) -zweifellos wieder auf Konj ugation zwischen Doppelbindung und gespanntem cr-System hin, Das Signal der al1ylstiindigen Protonen (2,5-H) erscheint bei 8= 1.84, und damit bei erheblich h6herem Feld als das der Protonen in 1, 6-Position (3.53)1 3 ), Die im Vergleich zum geslittigten System (2)1 22 ) ungew6hnliche Tieffeldabsorption von 1, 6-H ist in Einklang mit den entsprecbenden IJC-chemischen Verschiebungen: Mit 8=2.4 und 34.0 zeigt (2) typische Werte flir die zentralen bzw. seitlichen Kohlenstoffatome in Bicyclo(t,1.0jbutan-Derivaten I22 ,23 1 . In (1) wird die umgekehrte ReihenfoIge angetroffen, wobei die Lage des C-2, 5-Signais kaum verilndert ist; das Signal von Cot, 6 erscheint bei 8=48,3, und es ist damit um 45.9 ppm nach tieferem Feld verschoben(24,25J. Diese Tieffeldverschiebung riihrt von der Wechselwirkung zwischen dem 'IT·-Orbital der Doppelbindung und dem a,-Orbital des Bicyclo[1.1.0]butan-Systems her, und sie rmdet sich -nach Ringspannung abgestuft -auch bei anderen. in der Briefumschlag·Konformation fixierten Cyclopentenen(24). Ebenso wie die chemischen Verschiebungen zeigen die t3C-'H-Kopplungskonstanten in (1) und (2)

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Oxidationsreaktionen am Benzvalen: Ozonolyse,cis-Hydroxylierung, Epoxidation und Singulettsauerstoff-Addition

Cited by 11 publications

References 14 publications

Bullvalene Trisepoxide and Its Stereospecific Rearrangement to 2,8,12‐Trioxahexacyclo[8.3.0.0^3,90^4,60^5,130^7,11]tridecane: Two New C₃‐Symmetrical Oligocycles with Propeller Chirality

Bullvalene Trisepoxide and Its Stereospecific Rearrangement to 2,8,12‐Trioxahexacyclo[8.3.0.0^3,90^4,60^5,130^7,11]tridecane: Two New C₃‐Symmetrical Oligocycles with Propeller Chirality

Transformations of peroxide products of olefins ozonolysis

Benzvalen – Eigenschaften und Synthesepotential

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Oxidationsreaktionen am Benzvalen: Ozonolyse,cis-Hydroxylierung, Epoxidation und Singulettsauerstoff-Addition

Cited by 11 publications

References 14 publications

Bullvalene Trisepoxide and Its Stereospecific Rearrangement to 2,8,12‐Trioxahexacyclo[8.3.0.03,904,605,1307,11]tridecane: Two New C3‐Symmetrical Oligocycles with Propeller Chirality

Bullvalene Trisepoxide and Its Stereospecific Rearrangement to 2,8,12‐Trioxahexacyclo[8.3.0.03,904,605,1307,11]tridecane: Two New C3‐Symmetrical Oligocycles with Propeller Chirality

Transformations of peroxide products of olefins ozonolysis

Benzvalen – Eigenschaften und Synthesepotential

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Product

Resources

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Bullvalene Trisepoxide and Its Stereospecific Rearrangement to 2,8,12‐Trioxahexacyclo[8.3.0.0^3,90^4,60^5,130^7,11]tridecane: Two New C₃‐Symmetrical Oligocycles with Propeller Chirality

Bullvalene Trisepoxide and Its Stereospecific Rearrangement to 2,8,12‐Trioxahexacyclo[8.3.0.0^3,90^4,60^5,130^7,11]tridecane: Two New C₃‐Symmetrical Oligocycles with Propeller Chirality