13139-16-7

73-32-5

24424-99-5

13139-16-7

一般步骤：将L-异亮氨酸（1.31 g，10 mmol，1.0当量）溶于20.5 mL 1 M NaOH溶液中，置于冰浴中冷却。缓慢加入溶于7 mL二恶烷的二碳酸二叔丁酯（Boc2O，2.62 g，12 mmol，1.2当量）。反应混合物在环境温度下搅拌24小时。随后，用1 M NaOH调节反应液的pH至10，加入乙醚进行相分离。水相用1 M HCl酸化至pH 2，并用乙酸乙酯（EtOAc）萃取。合并的有机相用饱和食盐水洗涤，无水硫酸钠干燥。减压除去溶剂，得到BOC-L-异亮氨酸，为无色油状物（2.20 g，产率95%）。 IR (cm-1): 3292 (w), 2967 (m), 2934 (w), 2880 (w), 1713 (s), 1661 (m), 1504 (m), 1465 (w), 1394 (m), 1368 (s), 1242 (m), 1159 (s), 1121 (m), 1046 (m), 1019 (w), 857 (w), 778 (w), 657 (w). 1H NMR (500 MHz, CDCl3) δ: 0.94 (t, J = 7.3 Hz, 3H, H-6), 0.98 (d, J = 7 Hz, 3H, H-4), 1.15-1.29 (m, 1H, H-5a), 1.46 (s, 9H, H-9/10/11), 1.46-1.54 (m, partially overlapped, 1H, H-5b), 1.83-1.99 (m, 1H, H-3), 4.30 (dd, J = 8.9, 4.6 Hz, 1H, H-2), 5.02 (d, J = 8.9 Hz, 1H, NH). 13C NMR (125 MHz, CDCl3) δ: 11.8 (C-6), 15.7 (C-4), 25.0 (C-5), 28.5 (C-9/10/11), 37.9 (C-3), 58.0 (C-2), 80.2 (C-8), 155.9 (C-7), 177.2 (C-1). HRMS (ESI) m/z: [M-H]- calcd for C11H20NO4 230.13868, found 230.13926. [α]20D +3.6 (c 2.00, CH3OH) (Lit [3]: [α]25D +3.8 (c 1.01, CH3OH)).

参考文献：

[1] Tetrahedron Letters, 2005, vol. 46, # 38, p. 6537 - 6540

[2] Bioorganic and Medicinal Chemistry, 2010, vol. 18, # 17, p. 6340 - 6350

[3] Bioorganic and Medicinal Chemistry, 2014, vol. 22, # 14, p. 3573 - 3586

[4] Tetrahedron, 1992, vol. 48, # 37, p. 8007 - 8022

[5] Tetrahedron, 2006, vol. 62, # 31, p. 7274 - 7283