Enantioselective alkylative double ring-opening of epoxides derived from cyclic allylic ethers: synthesis of enantioenriched unsaturated diolsElectronic supplementary information (ESI) available: the preparation and characterisation of derivatives for ee determinations. See http://www.rsc.org/suppdata/ob/b2/b212404a/
Hodgson, David M.; Stent, Matthew A. H.; Štefane, Bogdan; Wilson, Francis X.; Hodgson David M.; Dyson Perrins Laboratory, Department of Chemistry, University of Oxford; Stent Matthew A. H.; Dyson Perrins Laboratory, Department of Chemistry, University of Oxford; Å tefane Bogdan; Dyson Perrins Laboratory, Department of Chemistry, University of Oxford; Wilson Francis X.; Roche Discovery (Welwyn)
Журнал:
Organic & Biomolecular Chemistry
Дата:
2003
Аннотация:
A screen of external chiral ligands has led to enantioselective organolithium-induced alkylative double ring-opening of 3,4-epoxytetrahydrofuran 1 with n-BuLi to give 3-methyleneheptane-1,2-diol 3 in 75% yield and 55% ee in the presence of bisoxazoline 10, and in up to 60% ee in the presence of (â )-sparteine 2. Extending the alkylative double ring-opening reaction to epoxides derived from oxabicyclo[n.2.1]alkenes (n = 2, 3) results in the formation of cycloalkenediols, which, when carried out in the presence of (â )-sparteine 2 affords products in up to 85% ee.
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