Stereoselective Substitution at Phenyl‐Substituted γ‐Lactols with Organometallic Compounds
1995; Wiley; Volume: 128; Issue: 9 Linguagem: Inglês
10.1002/cber.19951280904
ISSN0009-2940
AutoresAndreas Schmitt, Hans‐Ulrich Reißig,
Tópico(s)Synthetic Organic Chemistry Methods
ResumoAbstract A variety of monosubstituted γ‐lactols 4–6 were prepared in good yields by DIBAL reduction of the corresponding γ‐lactones 1–3 . The monophenyl‐substituted lactols 4b–6b were transformed into disubstituted tetrahydrofuran derivatives by replacement of the hydroxyl group by the alkyl residue of organometallic compounds used as nucleophiles. The diastereoselectivity of the substitution was found to depend strongly on the substitution pattern of the γ‐lactols. For the reaction of the 3‐ and 4‐substituted derivatives 4b and 5b , respectively, good to excellent trans selectivity was observed, while the 5‐substituted derivative reacted without any diastereoselectivity. These results were interpreted by means of the Felkin‐Anh model.
Referência(s)