Benzotriazol-1-yloxy-tris(dimethylamino)phosphonium hexafluorophosphate → 3(R)-(t-butoxycarbonylamino)-N-(1(S)-hydroxymethyl-2,2-dimethyl-propyl)succinamic acid benzyl ester

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Reaction Steps

As described in Example 1(f) for the preparation of N-(1(S)-benzyl-2-methoxyethyl)-3(R)-(t-butoxycarbonylamino)succinamic acid benzyl ester, N-t-butoxycarbonyl-D-aspartic acid β-benzyl ester (1.00 g, 3.10 mmol) and L-t-leucinol (400 mg, 3.40 mmol) were coupled with BOP to afford 1.20 g (90%) of 3(R)-(t-butoxycarbonylamino)-N-(1(S)-hydroxymethyl-2,2-dimethyl-propyl)succinamic acid benzyl ester as a white powder, mp 186-7° C. 1H NMR (CDCl3): δ 7.22 (s, 5H), 6.52 (d, 1H, J=9.3 Hz), 5.62-5.52 (m, 1H), 5.25 (dd, 2H, J=12.1, 18.7 Hz), 4.58-4.48 (m, 1H), 3.90-3.78 (m, 2H), 3.58-3.50 (m, 1H), 3.22-3.10 (m, 1H), 2.78 (dd, 1H, J=5.9, 17.7 Hz), 2.52-2.45 (m, 1H), 1.22 (s, 9H), 0.98 (s, 9H). IR: 3322, 2960 1730, 1664 1528, 1367, 1249, 1165, 1050 cm-1. Anal. Calculated for C22H34N2O6 : C, 62.52; H, 8.12; N, 6.63. Found: C, 62.20; H, 8.13; N, 6.62.

Provenance & Evidence