反应详情

As described in Example 1(b) for the preparation of 3(R)-amino-N-(2,2-dimethyl-1(S)-(methylcarbamoyl)propyl)succinamic acid benzyl ester trifluoroacetate salt, crude 3(R)-(t-butoxycarbonylamino)-N-(2,2-dimethyl-1(S)-(methylcarbamoyl)propyl)succinamic acid allyl ester was deprotected after 2 hours. Flash column chromatography with 0.5% TFA/7% MeOH/CHCl3 gave 2.46 g (87%) of 3(R)-amino-N-(2,2-dimethyl-1(S)-(methylcarbamoyl)propyl)succinamic acid allyl ester trifluoroacetate salt as a colorless foam. 1H NMR (CD3OD): δ 5.96 (ddt, 1H, J=5.6, 10.6, 17.1 Hz), 5.35 (ddd, 1H, J=1.6, 3. 1, 17.1 Hz), 5.25 (ddd, 1H, J=1.2, 2.5, 10.3 Hz), 4.66 (ddd, 2H, J=1.2, 1.3, 5.9 Hz), 4.34 (dd, 1H, J=5.6, 7.8 Hz), 4.21 (s, 1H), 3.03 (dd, 1H, J=5.6, 17.4 Hz), 2.94 (dd, 1H, J=7.5, 17.4 Hz), 2.71 (d, 3H, J=5.0 Hz), 1.46 (s, 9H), 0.99 (s, 9H). IR (KBr): 3413, 2966, 1672, 1656, 1207, 1143 cm−1. HRFABMS: Calculated for C14H25N3O4Na (M+Na+): 322.1743. Found: 322.1747. Anal. Calculated for C14H25N3O4•2.5 F3COOH•0.5 CHCl3: C, 36.36; H, 4.38; N, 6.52. Found: C, 36.34; H, 4.25; N, 6.51.