p-Toluenesulfonic acid → 3-Hydroxy-2-methyl-2-(methylamino)propanoic acid tert-butyl ester

Participants

Reaction Steps

A 255 mg portion of alcohol 11 (0.88 mmol) was treated with 1 eq p-toluenesulfonic acid (167 mg) as described in the preparation of 12a. The resulting solid was added to 15 mL of 10% Na2CO3 and extracted with 3×15 mL of EtOAc. The combined organic layers were subject to the usual work up. Purification via silica gel column chromatography (10% CH3OH in CH2Cl2) afforded 12b (115 mg, 69%) as a colorless oil: 1H NMR (CDCl3) δ 1.24 (3H, s), 1.48 (9H, s), 2.32 (3H, s), 3.52 (1H, d, J=10.8), 3.64 (1H, d, J=10.8). HRMS Calcd for C9H19NO3: 189.13649. Found 189.13627. Anal. (C9H19NO3) Calcd C, 57.12; H, 10.12, N, 7.40. Found C, 55.87; H, 10.05, N, 7.18.

Provenance & Evidence