Reaction Steps
The silyl ether 4 (96.0 g, 136.4 mmol) in THF (600 mL) was treated with hydrogen fluoride-pyridine (70% HF in pyridine, 30 mL) at 0° C. for 4 h under a N2 atmosphere. The resultant mixture was diluted with AcOEt (600 mL) and washed with H2O (2×300 mL). The organic layer was dried (MgSO4) and concentrated at reduced pressure. The residue was purified by silica gel column chromatography (CH2Cl2 /AcOEt 10:1) to give 61.6 g (97%) of 5 as a white solid. Rf (CH2Cl2 /AcOEt 10:1) 0.29. 1H-NMR(CDCl3 +D2O): 1.95 (s, 3H, 5-Me), 2.53 (m, 2H, 2'-H), 4.00 (m, 2H, 5'-H), 4.25 (m, 1H, 4'-H), 4.71 (s, 2H, O--CH2 --Ph), 5.51 (s, 2H, N--CH2 --O), 5.60 (m, 1H 3'-H), 6.36 (dd, 1H, J=7.6, 6.6 Hz, 1'-H), 7.25-7.66 (m, 9H, 6 -H and aromatic-H), 8.05 (d, 2H, J=7.1 Hz, aromatic-H). 13C-NMR(CDCl3): 13.29 (-, 5-Me), 37.82 (+, 2'-C), 62.54 (+, 5'-C), 70.73 (+, O--C--Ph), 72.25 (+, N--C--O), 75.82 (-, 4'-C), 85.43 (-, 3'-C), 86.13 (-, 1'-C), 110.41 (+, 5-C), 127.65, 128.36, 128.59 (-, aromatic-C), 129.34 (+, aromatic-C), 129.69 (-, 6-C), 133.60, 135.40 (-, aromatic-C), 137.87 (+, aromatic-C), 151.18 (+, 2-C), 163.65 (+, 4C), 166.11 (+, benzoyl C=O).
