Results 71 to 80 of about 161 (128)
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Piperidine dispiro-1,2,4-trioxane analogues
Bioorganic & Medicinal Chemistry Letters, 2008Dispiro N-Boc-protected 1,2,4-trioxane 2 was synthesised via Mo(acac)(2) catalysed perhydrolysis of N-Boc spirooxirane followed by condensation of the resulting beta-hydroperoxy alcohol 10 with 2-adamantanone. N-Boc 1,2,4-trioxane 2 was converted to the amine 1,2,4-trioxane hydrochloride salt 3 which was subsequently used to prepare derivatives (4-7 ...
Sunil, Sabbani +6 more
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Tetrahedron, 1994
Abstract The dispiroketones 4–6 have been synthesized and rearranged by treatment with acids yielding the bicyclic enone 36 under kinetic control and the [3.3.3]propellane 37 under thermodynamic control. The corresponding alcohols 10–12 all yield the [3.3.3]propellane 41. The rearrangement of [7,7-D2]-12 to [8,8-D2]-41 proceeds stereospecifically and
Lutz Fitjer +2 more
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Abstract The dispiroketones 4–6 have been synthesized and rearranged by treatment with acids yielding the bicyclic enone 36 under kinetic control and the [3.3.3]propellane 37 under thermodynamic control. The corresponding alcohols 10–12 all yield the [3.3.3]propellane 41. The rearrangement of [7,7-D2]-12 to [8,8-D2]-41 proceeds stereospecifically and
Lutz Fitjer +2 more
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ChemInform Abstract: Syntheses of Dispiro[2.1.4.1]decane and Dispiro[2.0.3.3]decane.
ChemInform, 2001AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
John E. Baldwin +2 more
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New Dispiro Compounds: Synthesis and Properties
Organic Letters, 2008We report the synthesis and structural characterization of two dispiro compounds. These two positional isomers have been designed and synthesized through an efficient method. Because of the rigidity and orthogonality of the spiro bridge, both molecules exhibit a well-defined architecture which consists of two fluorene rings connecting to an ...
Poriel, Cyril +3 more
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ChemInform Abstract: DISPIRO‐DITHIETANE
Chemischer Informationsdienst. Organische Chemie, 1970AbstractDie Cycloalkanone (Ia)‐(Ie) reagieren bei Behandlung mit Formaldehyd in Gegenwart von Alkali zu den Tetra‐methylol‐Verbindungen (II), die zu (III) mesyliert wurden.
G. SEITZ, W. D. MIKULLA
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Novel Dispiro Iminodioxolane Derivatives: Synthesis by Reaction of Isocyanides with Ninhydrin
Journal of Chemical Research, 2003 The reaction of isocyanides 1 with two equivalent of ninhydrin 2 gives C s symmetry dispiro iminodioxolanes 3 at refluxing conditions in chloroform in fairly high yields.
Hamid Reza Bijanzadeh +2 more
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Organic Letters, 2012
An efficient and stereoselective reaction between 3-isothiocyanato oxindoles and isatins/isatinimines has been developed to afford structurally diverse dispiro[oxazolidine-2-thione]bisoxindoles and dispiro[imidazolidine-2-thione]bisoxindoles in excellent results under mild conditions. The potential of asymmetric induction by means of a chiral auxiliary
Yan-Yan, Han +5 more
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An efficient and stereoselective reaction between 3-isothiocyanato oxindoles and isatins/isatinimines has been developed to afford structurally diverse dispiro[oxazolidine-2-thione]bisoxindoles and dispiro[imidazolidine-2-thione]bisoxindoles in excellent results under mild conditions. The potential of asymmetric induction by means of a chiral auxiliary
Yan-Yan, Han +5 more
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Ring inversion in dispiro[2,2,2,2]decane
Journal of the Chemical Society D: Chemical Communications, 1970The title compound (I), which contains a cyclohexane ring with spiro-bound cyclopropanes at either end, has been found to have a barrier (Ea) to ring inversion of 12·1 ± 0·4 kcal mol–1; the axial–equatorial chemical-shift difference is 1·21 p.p.m., an unusually large value.
Joseph B. Lambert +3 more
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Tetrahedron, 1994
Abstract The dispiranes 10–12 have been synthesized and rearranged by treatment with acids. With 10, an initial C3-C4 ring enlargement leads to [3.3.3]propellane 21, with 11, an initial C4-C3 ring contraction leads to pentalene 37, and with 12, an initial C4-C5 ring enlargement leads to 42, 43, 44 or 45, depending on the reagent used.
Lutz Fitjer +3 more
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Abstract The dispiranes 10–12 have been synthesized and rearranged by treatment with acids. With 10, an initial C3-C4 ring enlargement leads to [3.3.3]propellane 21, with 11, an initial C4-C3 ring contraction leads to pentalene 37, and with 12, an initial C4-C5 ring enlargement leads to 42, 43, 44 or 45, depending on the reagent used.
Lutz Fitjer +3 more
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Two Syntheses of Dispiro[2.1.3.2]decane
Organic Letters, 1999Dispiro[2.1.3.2]decane, the first of the five possible dispirodecanes constituted from one three-membered, one four-membered, and one five-membered ring to be synthesized, has been prepared efficiently in four steps from methylenecyclopropane and again in five steps from methylenecyclobutane.
John E. Baldwin, Rajesh Shukla
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