反应详情

Methyl (3-hydroxy)-2-(S)-(t-butoxycarbonylamino)propionate (58 g, 196 mmol), dry methylene chloride (150 ml), p-toluenesulfonyl chloride (43.35 g, 227.4 mmol), 4-(dimethylamino)pyridine (2.4 g, 19.6 mmol) and pyridine (30 ml, 371 mmol) were combined and stirred at room temperature overnight. The reaction solution was concentrated in vacuo to a pale yellow oil. The oil was stored in vacuo overnight, then the white solid that formed was isolated to give 75.33 g of crude product. The product was triturated in petroleum ether (approximately 200 ml) to yield methyl 3-(p-toluenesulfonyloxy)-2-(S)-(t-butoxycarbonylamino)propionate: n.m.r.: (CDCl3, 90 MHz): δ7.72, 7.31 (2x dd, 4, aromatic protons), 5.26 (m, 1, nitrogen proton), 4.48 (m, 1, C-2 proton), 4.32 (m, 2, C-3 protons), 3.68 (s, 3, methyl protons of methyl ester), 2.44 (s, 3, methyl protons of toluene moiety), 1.40 (s, 9, protons of t-butyl moiety); i.r. (CHCl3): 3435, 3019, 1753, 1711, 1502, 1369, 1351, 1250, 1215, 1190, 1177 cm-1 ; m.s.: 279, 210, 172, 91, 41;

1. concentrationThe reaction solution was concentrated in vacuo to a pale yellow oil
2. customwas stored in vacuo overnight
3. customthe white solid that formed
4. customwas isolated
5. customto give 75.33 g of crude product
6. customThe product was triturated in petroleum ether (approximately 200 ml)