反应详情

To a stirred cooled (ice-bath) solution of methyl 2-{[(benzyloxy)carbonyl]amino}-3-({2-[(tert-butoxycarbonyl)amino]ethyl}thio)-3-phenylpropanoate (7a) (1.20 g) and methanol (0.284 mL) in ethyl acetate (2 mL) was added dropwise from a syringe acetyl chloride (0.43 mL) and the mixture stirred in the ice bath for an additional 10 min and then at RT for 50 min. Excess Et2O was added and the white solid collected, dissolved in water, treated with an excess of sat. aqueous K2CO3 and extracted once with CH2Cl2 and twice with Et2O. The dried organics (MgSO4) were filtered and the solvent removed to yield the title compound as an oil (0.86 g, 90%). The proton NMR displayed a mixture of diastereomers of approximate ratio 7:3; the major diastereomer is reported. 1H NMR (300 MHz, CDCl3) δ1.46 (s, 2H, exchangeable), 2.47 (t, 2H), 2.76 (t, 2H), 3.66 (s, 3H), 3.35 (d, 1H), 4.75 (t, 1H), 5.09 (m, 2H), 5.76 (d, 1H, exchangeable), 7.28-7.34 (m, 10H). MS APCI, m/z=389(M+1). HPLC Method A: 2.27 min.

1. customthe white solid collected
2. dissolutiondissolved in water
3. additiontreated with an excess of sat. aqueous K2CO3
4. extractionextracted once with CH2Cl2 and twice with Et2O
5. filtrationThe dried organics (MgSO4) were filtered
6. customthe solvent removed