Preparation of 12. NaCNBH 3 (0.8 equiv) was added to 9 (310mg) and ammonium acetate (8 equiv) in MeOH (7 mL). 12 was isolated by vacuum filtration as a hydroscopic solid after 18h stirring at RT. Data for 12: mp 167–171°. 1 H NMR (300MHz, D 2 O) δ 4.13 (2H, s); 4.49 (2H, s); 6.13 (1H, m); 6.33 (1H, m); 6.76 (1H, m). 13 C NMR (D 2 O) δ 41.4, 51.6, 108.6, 113.3, 123.0, 126.7, 177.5. IR(KBr) 3191, 2361, 1576 cm −1 . Found C, 49.12; H, 6.98; N, 16.46. ...