Synthesis of 8-methyl-6-thio-7-(β-D-xylopyranosyl)theophylline. Conformational study of its peracetyl derivatives. Molecular mechanics calculations and minimum-energy geometries of 8-methyl-7-(2′,3′,4′-tri-O-acetyl-β-D-xylopyranosyl)theophylline and 8-methyl-6-thio-7-(2′,3′,4′-tri-O-acetyl-β-D-xylopyranosyl)theophylline | Publicación