反应详情

Step K (2): Thionyl chloride (1.22 mL, 16.9 mmol) was added to a round bottom flask charged with a solution of (S)-2-(tert-butoxycarbonyl(methyl)amino)hex-5-enoic acid (2.06 g, 8.47 mmol) from Step K (1) in MeOH at 0° C. After complete addition, heated at reflux for 2 h. Cooled to rt, concentrated in vacuo, and removed residuals on high vacuum overnight. This afforded 1.64 g (quantitative yield) of the title compound as an off-white solid. LC-MS (M+H)+=158.3; 1H NMR (500 MHz, CDCl3) δ ppm 2.09-2.27 (m, 3H) 2.29-2.43 (m, 1H) 2.71-2.81 (m, 3H) 3.77-3.88 (m, 3H) 5.04 (d, J=10.07 Hz, 1H) 5.12 (d, J=17.09 Hz, 1H) 5.68-5.82 (m, 1H) 9.59-9.72 (br s, 1H) 9.99-10.12 (br s, 1H).

1. additionAfter complete addition
2. temperatureheated
3. temperatureat reflux for 2 h
4. concentrationconcentrated in vacuo
5. customremoved residuals on high vacuum overnight