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