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Titolo:
Efficient desymmetrization of meso-cis-1,2-cyclohexanedimethanol with differentiation between diastereotopic and enantiotopic C-H bonds by (-)-sparteine-mediated deprotonation
Autore:
van Bebber, J; Ahrens, H; Frohlich, R; Hoppe, D;
Indirizzi:
Univ Munster, Inst Organ Chem, D-48149 Munster, Germany Univ Munster Munster Germany D-48149 rgan Chem, D-48149 Munster, Germany
Titolo Testata:
CHEMISTRY-A EUROPEAN JOURNAL
fascicolo: 6, volume: 5, anno: 1999,
pagine: 1905 - 1916
SICI:
0947-6539(199906)5:6<1905:EDOMWD>2.0.ZU;2-T
Fonte:
ISI
Lingua:
ENG
Soggetto:
SINGLE-ELECTRON-TRANSFER; MESO/DL STEREOISOMERIC MIXTURES; ENANTIOSELECTIVE SYNTHESIS; KINETIC RESOLUTION; ASYMMETRIC-SYNTHESIS; ORGANIC-SYNTHESIS; (-)-SPARTEINE-ASSISTED DEPROTONATION; TETRAPROPYLAMMONIUM PERRUTHENATE; ALPHA-METHYLBENZYLLITHIUM; ABSOLUTE-CONFIGURATION;
Keywords:
desymmetrization; isotope effects; kinetic resolution; stereotopic differentiation;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
99
Recensione:
Indirizzi per estratti:
Indirizzo: Hoppe, D Univ Munster, Inst Organ Chem, Corrensstr 40, D-48149 Munster, Germany Univ Munster Corrensstr 40 Munster Germany D-48149 ster, Germany
Citazione:
J. van Bebber et al., "Efficient desymmetrization of meso-cis-1,2-cyclohexanedimethanol with differentiation between diastereotopic and enantiotopic C-H bonds by (-)-sparteine-mediated deprotonation", CHEM-EUR J, 5(6), 1999, pp. 1905-1916

Abstract

The deprotonation of a dicarbamate prepared from cis-1,2-cyclohexanedimethanol by sec-butyllithium/(-)-sparteine proceeds with efficient selection between the enantiotopic branches and their diastereotopic protons with high preference for the pro-S proton at the R branch to afford the intermediate,configurationally stable lithium compound as a single diastereomer. Trapping of this intermediate by electrophiles (DOMe, CO2, CH3I, Me3SiCl, or R3SnCl) takes place with retention of the configuration to yield highly enantiomerically and diastereomerically enriched substitution products, which are easily converted to diols, to anellated tetrahydrofurans, or to gamma-lactones. The chiral base is also capable of efficient kinetic resolution of theracemic alpha-deuterated starting material, by the utilization of an extraordinarily high kinetic H/D isotope effect within the deprotonation step. The, presumably first example of the kinetic resolution of a racemic stannane by lithiodestannylation, utilizing methyllithium/(-)-sparteine, is reported.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 17/02/20 alle ore 17:24:11