82819-41-8Relevant academic research and scientific papers
Stereochemical Control in Reactions of Nucleophiles with Oxocarbenium Ions Formed by Intramolecular Opening of Activated Epoxides by Neighboring Carbonyl Groups
Fotsch, Christopher H.,Chamberlin, A. Richard
, p. 4141 - 4147 (2007/10/02)
Tandem cyclization/reduction and cyclization/alkylation processes for the stereoselective synthesis of 2,5-disubstituted tetrahydrofurans, 2,6-disubstituted tetrahydropyrans, and 2,7-disubstituted oxepanes are described.In the presence of Lewis acids or TMSOTf, γ,δ-, δ,ε- and ε,ζ-epoxy ketones and esters undergo cyclization to the corresponding oxocarbenium ions, which react in situ with a variety of organosilanes and organoaluminum reagents to give the substituted oxacyclic products.For the synthesis of substituted tetrahydrofurans, the stereochemical control of the addition process was much higher with TMSOTf than BF3*OEt2.
DIASTEREOSELECTIVITY IN THE DIRECTED ALDOL CONDENSATION OF 2-TRIMETHYLSILOXYFURAN WITH ALDEHYDES. A STEREODIVERGENT ROUTE TO THREO AND ERYTHRO δ-HYDROXY-γ-LACTONES
Jefford, Charles W.,Jaggi, Danielle,Boukouvalas, John
, p. 4037 - 4040 (2007/10/02)
Threo and erythro-δ-hydroxy-4a,β-unsaturated γ-lactones are obtained with useful diastereoselection by condensing 2-trimethylsiloxyfuran and aldehydes by variying the reaction conditions.A stereomechanistic rationale is presented together with a practical two-step synthesis of the threo and erythro 5-hydroxy-4-decanolides (L-factors).
