反应详情

Following general procedure A: ((R)-2-amino-1-phenyl-ethyl)-carbamic acid tert-butyl ester (269 mg, 1.14 mmol), tetrahydro-4H-pyran-4-one (0.12 ml, 1.3 mmol) and NaBH(OAc)3 (340 mg, 1.60 mmol) in CH2Cl2 (8.0 ml) was stirred at room temperature for 18 hours. Standard work-up and purification by flash column chromatography on silica (CH2Cl2/MeOH, 19:1) gave [(R)-1-phenyl-2-(tetrahydro-pyran-4-ylamino)-ethyl]-carbamic acid tert-butyl ester as a colorless oil (333 mg, 91%). 1H NMR (CDCl3) δ 0.80-1.36 (m, 3H), 1.41 (s, 9H), 1.68-1.82 (m, 2H), 2.61 (tt, 1H, J=10.3, 4.1 Hz), 2.93 (d, 2H, J=5.1 Hz), 3.35 (tdd, 2H, J=11.6, 5.6, 2.2 Hz), 3.88-3.96 (m, 2H), 4.74 (br s, 1H), 5.45 (br d, 1H, J=5.7 Hz), 7.22-7.35 (m, 5H).

1. customStandard work-up and purification by flash column chromatography on silica (CH2Cl2/MeOH, 19:1)