- Syntheses of dispiro[2.1.4.1]decane and dispiro[2.0.3.3]decane
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Efficient syntheses of the hitherto unknown hydrocarbons dispiro[2.1.4.1]decane and dispiro-[2.0.3.3]decane have been realized through reaction sequences involving spiro[3.4]octan-2-one and spiro[3.4]octan-5-one as key intermediates. (C) 2000 Elsevier Science Ltd.
- Baldwin,Keene,Shukla
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- SPIRO COMPOUNDS AND PHARMACEUTICAL USE THEREOF
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The Spiro compound represented by the following general formula [Ia], its pharmaceutically acceptable salt or a solvate thereof
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Page/Page column 77
(2009/07/17)
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- Cyclobutyl phenyl sulfoxide and (SR)-cyclobutyl p-tolyl sulfoxide: New reagents for the spiroannelation of cyclopentanone
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Cyclobutyl phenyl sulfide 2, cyclobutyl phenyl sulfoxide 3 and (SR)- cyclobutyl p-tolyl sulfoxide (SR)-8 have been synthesized and used for the spiroannelation of cyclopentanone. In the most effective sequence, lithiated 3 is added to ketones with formation of β-hydroxy sulfoxides 4a-g, which are ring enlarged and hydrolyzed to cyclopentanones 6a-e and sulfanylcyclopentene 6f, respectively, after reduction to β-hydroxy sulfides 5a-f. In an asymmetric version using (SR)-8, partial racemization during ring enlargement was observed.
- Fitjer, Lutz,Schlotmann, Werner,Noltemeyer, Mathias
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p. 4985 - 4988
(2007/10/02)
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- Synthesis and rearrangement of dispiro[2.0.3.4]-, dispiro-[3.0.3.3]- and dispiro[2.1.3.3]undecanes-preferred C4-C5 over C3-C4 and C4-C3 over C5-C6 rearrangements
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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 pe
- Fitjer,Rissom,Kanschik,Egert
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p. 10879 - 10892
(2007/10/02)
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