title: Stereoselective synthesis of functionalized trans-2,5-disubstituted tetrahydrofurans
abstract: [reaction: see text] The addition of the titanium enolates of N-acetyl, N-propionyl, and N-bromoacetyl (R)-oxazolidin-2-ones to gamma-lactol 2, derived from (S)-glutamic acid, afforded trans- and cis-2,5-disubstituted tetrahydrofurans (trans/cis ratio: R = H, 2:1; R = Me, 8:1; R = Br, 10:1) after desilylation with aqueous HF/CH3CN. Chromatographic separation and LiBH4 reduction allowed the efficient preparation of the corresponding trans-2,5-disubstituted tetrahydrofuran diols and the recovery of the chiral auxiliary.
authors.affiliation: Instituto de Quimica, Unicamp, Campinas, SP, Brazil. pilli@iqm.unicamp.br
authors.initials: RA
authors.lastname: Pilli
authors.initials: VB
authors.lastname: Riatto
authors.initials: I
authors.lastname: Vencato