Reaction sof d-lyxose and d-xylose with 2-methoxypropene under kinetic conditions

Efficient “Dehomologation” of Di-O-isopropylidenehexofuranose Derivatives To Give O-Isopropylidenepentofuranoses by Sequential Treatment with Periodic Acid in Ethyl Acetate and Sodium Borohydride

“…Compounds 1 and 11 were obtained from Aldrich, and 3 , 5 , 7 , and 9 10 were prepared as described. Products 2 , 4 , 8 , 10 , and intermediate 12 7 were reported previously and have melting points and 1 H and 13 C NMR data in harmony with literature values.…”

New Unnatural Gallotannins: A Way toward Green Antioxidants, Antimicrobials and Antibiofilm Agents

“…1,2,3,4,6-penta-O-galloyl-αβ-D-glucose (PGG) was synthesized according to Ren et al [18] and its identity and purity was confirmed by NMR spectroscopy. 1 H NMR (600.13 MHz, methanol-d 4 ) δ: 7.21, 7.11, 7.11, 7.05, 6.99, 6.98, 6.95,6.93, 6.92, 6.90 (10 × s, 20 H, galloyl), 6.70 (d, 1H, J 1,2 = 3.5 Hz, H-1α), 6.24 (d, 1H, J 1,2 = 8.3 Hz, H-1β), 6.13 (dd, 1H, J 3,4 = 9.9 Hz, H-3α), 5.90 (dd, 1H, J 3,4 = 9.9 Hz, H-3β), 5.71 (dd, 1H, J A reaction mixture of 2,3-O-isopropylidene-D-lyxose [36], (1 g; 5.3 mmol), K 2 CO 3 (0.8 g) methanol (15 mL), and 37% aqueous solution of formaldehyde (15 mL; 147 mmol) was refluxed in argon atmosphere at 85 • C for 40 h. The reaction mixture was neutralized with 10% aq sulphuric acid and evaporated. Extraction with chloroform (4 × 30 mL) gave a combined fraction that was dried over anhydrous MgSO 4 and concentrated.…”

Synthesis of α-galactosyl ceramide and the related glycolipids for evaluation of their activities on mouse splenocytes

“…Execution of this synthetic plan is shown in Scheme 1. The 2,3-dihydroxy groups of D-lyxose were selectively protected as an acetal using 2,2-dimethoxypropane, 16 and the primary hydroxyl group was subsequently protected as a trityl ether, 17 giving 11 in 71% yield. Wittig olefination of 11 using Ph 3 PC 13 H 27 Br or Ph 3 PC 4 H 9 Br in the presence of lithium hexamethyldisilazide (LHMDS) 18 yielded alkenes 12 (93% yield) and 13 (85% yield).…”