Synthesis 2001(7): 1013-1022
DOI: 10.1055/s-2001-14902
PAPER
© Georg Thieme Verlag Stuttgart · New York

Stereoselective Synthesis of 2,2,6,6-Tetrasubstituted Tetrahydropyrans

David Díez Martín*, Isidro S. Marcos, Pilar Basabe, Ricardo E. Romero, Rosalina F. Moro, Wenceslao Lumeras, Lucena Rodríguez, Julio G. Urones*
Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad de Salamanca, 37008 Salamanca, Spain
Fax: +34(92)3294574; e-Mail: ddm@gugu.usal.es; jgu@gugu.usal.es;
Further Information

Publication History

Received 17 January 2001
Publication Date:
30 September 2004 (online)

Abstract

A new entry to the synthesis of 3-hydroxy-2,2,6,6-tetrasubstituted tetrahydropyrans has been achieved, avoiding problems encountered in the use of double bond assisted endo-tet cyclization reactions. These compounds are precursors of β-pyrones present in antiviral compounds.

24

Crystal data for 23a: C9H18O5, M = 174.23, monoclinic, space group C2, a = 10.971(2), b = 5.711(7), c = 16.242(2)Å, β = 105.63(1)°, V = 980.0(2)Å3, Z = 4, D c = 1.181 g cm-3, µ(Cu-Kα) = 7.07 cm-1, F(000) = 384. Data for compound 23a, 924 independent reflections, 2θ < 64.96°, were measured on a Seifert XRD 3000 rotating anode diffractometer with Cu-Kα radiation (graphite monochromator) using ω-scans. The structures were solved by direct methods and the non-hydrogen atoms were refined anisotropically by full-matrix least squares based on F 2 to give R1 = 0.0497 and wR2 = 0.1162 for 924 independent observed reflections [|Fo| > 4σ(|Fo|)]