Stereoselective Synthesis of
Functionalized <i>trans</i>-2,5-Disubstituted
Tetrahydrofurans
Ronaldo A. Pilli
Valéria B. Riatto
Ivo Vencato
10.1021/ol991194u.s002
https://acs.figshare.com/articles/journal_contribution/Stereoselective_Synthesis_of_Functionalized_i_trans_i_-2_5-Disubstituted_Tetrahydrofurans/3761358
The addition of the titanium enolates of <i>N</i>-acetyl, <i>N</i>-propionyl, and <i>N</i>-bromoacetyl (<i>R</i>)-oxazolidin-2-ones to γ-lactol <b>2</b>, derived from (<i>S</i>)-glutamic
acid, afforded <i>trans</i>- and <i>cis</i>-2,5-disubstituted tetrahydrofurans (<i>trans</i>/<i>cis</i> ratio: R = H, 2:1; R = Me, 8:1; R = Br, 10:1) after desilylation with
aqueous HF/CH<sub>3</sub>CN. Chromatographic separation and LiBH<sub>4</sub> reduction allowed the efficient preparation of the corresponding <i>trans</i>-2,5-disubstituted
tetrahydrofuran diols and the recovery of the chiral auxiliary.
1999-12-10 00:00:00
ci
Chromatographic separation
Stereoselective Synthesis
HF
CN
tetrahydrofuran
titanium enolates
tran
disubstituted
LiBH 4 reduction