Steric factors in the cationic rearrangement of substituted cyclobutanes

Lillien, Irving; Handloser, L.

doi:10.1021/ja00736a020

Cited by 8 publications

(1 citation statement)

References 5 publications

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“…Rotary evaporation at ∼80 mmHg/room temperature and chromatography (EtOAc:hexanes 0:1, 1:4, 1:1) gave the product 43 (1.84 g, 16.1 mmol, 81%, containing ∼3% of the cis isomer) as a colorless oil. Spectral data were in accord with those reported in the literature …”

Section: Methodssupporting

confidence: 87%

Studies on Mercury(II)-Mediated Opening of Bi- and Tercyclopropane Arrays

Barrett

Tam

1997

J. Org. Chem.

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The first examples of the mercury(II)-mediated ring opening of bicyclopropane and tercyclopropane arrays have been investigated. The presence of an adjacent cyclopropyl group dramatically increased the rate of the mercury-mediated opening of the first cyclopropane in a cyclopropane array. In contrast to the mercury-mediated ring opening of monocyclopropanes which usually undergo a concerted ring-opening mechanism, electrophilic openings of cyclopropane arrays occurred through a stabilized, free carbocation. Excellent regio-and stereoselectivities were observed in the mercurymediated intramolecular openings of the second cyclopropanes in the cyclopropane arrays, giving rise to the formation of enantiomerically pure, highly substituted tetrahydrofurans. Scheme 2. Mercury-Mediated Opening of Bicyclopropanedimethanol 3 Scheme 3. Formation of Acetonides 26 and 28 Scheme 4. Mercury-Mediated Intramolecular Openings of 23 and 24 Hg(II)-Mediated Opening of Bi-and Tercyclopropane Arrays

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Section: Methodssupporting

confidence: 87%

Studies on Mercury(II)-Mediated Opening of Bi- and Tercyclopropane Arrays

Barrett

Tam

1997

J. Org. Chem.

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Über den stereochemischen Verlauf von S _N 2‐Reaktionen an cis ‐ und trans ‐3‐Äthoxycyclobutyl‐Verbindungen

Elgomati¹,

Gasteiger²,

Lenoir³

et al. 1976

Chem. Ber.

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O n the Stereochemical Course of SJ-Reactions in cis-and trans-3-Euloxyc~clohu~l CompoundsThe nucleophilic substitution of 3-ethoxycyclobutyl bromide and p-bromobenzenesulfonate by acetate, azide, bromide and iodide have been investigated. The kinetically controlled bimolecular substitution by acetate and azide proceed with configurational inversion at the reactive site. Partial retention is observed in those cases in which a consecutive multiple substitution involving bromide or iodide is taking place. Predominant retention is observed in the reaction of cis-ethoxycyclobutyl compounds with bromide or iodide. In these reactions thermodynamic equilibrium is established in which the respective cis-isomer prevails.Aufgrund der beobachteten Reaktionen bei nucleophiler Substitution an Phosphorverbindungen mit 4-Ring"2) und der Ergebnisse einer theoretischen Behandlung der mechanistischen Grenzfdle nucleophiler Substitution

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Stereoselektive Synthese von 3‐substituierten Cyclobutanolen und Folgeprodukten

Dehmlow

Büker

1993

Chem. Ber.

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Stereoselective Synthesis of 3-Substituted Cyclobutanols and Products Derived TherefromDie Reduktion der Cyclobutanone zu den Cyclobutanolen 3 und 4 wurde rnit verschiedenen Reduktionsmitteln erprobt (Tab. 1). Wie zu erwarten, liefert das sterisch anspruchsvolle Lithium-tri-tert-butoxyaluminiumhydrid die hochste cis-Stereoselektivitat von 95 bis fast 100%. Somit sind die cis-Verbindungen 3 gut zuganglich. Dagegen wurde keine einfache Methode zur reduktiven Darstellung der trans-Verbindungen 4 aufgefunden. Selbst die Lewis-sauren Reduktionsmittel wie DIBAH liefern zwar erhohte, aber praparativ nicht ausreichende trans-Selektivitaten.Ein anderer potentieller Weg zu den Verbindungen 4 beginnt rnit der Dichlorketen-Addition an Alkine. So lassen sich z.B. 5a,b['03111 rnit ZdTMEDNEisessig zu 6a,b reduzieren" ' 1. Die erhoffte ein-oder zweistufige Reduktion bzw.

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Steric factors in the cationic rearrangement of substituted cyclobutanes

Cited by 8 publications

References 5 publications

Studies on Mercury(II)-Mediated Opening of Bi- and Tercyclopropane Arrays

Studies on Mercury(II)-Mediated Opening of Bi- and Tercyclopropane Arrays

Über den stereochemischen Verlauf von S _N 2‐Reaktionen an cis ‐ und trans ‐3‐Äthoxycyclobutyl‐Verbindungen

Stereoselektive Synthese von 3‐substituierten Cyclobutanolen und Folgeprodukten

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Steric factors in the cationic rearrangement of substituted cyclobutanes

Cited by 8 publications

References 5 publications

Studies on Mercury(II)-Mediated Opening of Bi- and Tercyclopropane Arrays

Studies on Mercury(II)-Mediated Opening of Bi- and Tercyclopropane Arrays

Über den stereochemischen Verlauf von S N 2‐Reaktionen an cis ‐ und trans ‐3‐Äthoxycyclobutyl‐Verbindungen

Stereoselektive Synthese von 3‐substituierten Cyclobutanolen und Folgeprodukten

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Über den stereochemischen Verlauf von S _N 2‐Reaktionen an cis ‐ und trans ‐3‐Äthoxycyclobutyl‐Verbindungen