Acetic Acid → 4-methoxybenzyl [(1R)-1-[(R)-{[tert-butyl(dimethyl)silyl]oxy}(phenyl)methyl]-5-(4-nitrophenyl)-4-oxopentyl]carbamate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of nitrophenyl acetylene (from Step F, 41 g, 65.5 mmol) in DMF (40 ml) was added pyrrolidine (14 mL, 196.5 mmol) and the resulting mixture heated at 80° C. for 3 h. The mixture was cooled to room temperature and a 10% solution of acetic acid in water (110 ml) was added, and the resulting solution stirred at room temperature for another 3 h. The mixture was poured into water (300 ml) and extracted with EtOAc (3×250 ml); combined EtOAc layers were washed with water (2×250 ml), sat. NaCl (100 ml), dried over MgSO4, filtered and evaporated. The residue was purified by Horizon Flash 75 eluting with a gradient rising from 100% Hexanes to 50% EtOAc in Hexanes to give 34 g (81%) as a dark orange oil. 1H NMR (500 MHz, CDCl3): 8.17-8.14 (m, 2H), 7.32-7.23 (m, 9H), 6.87 (d, J=8.4 Hz, 2H), 4.96 (d, J=12.2 Hz, 1H), 4.90 (d, J=12.1 Hz, 1H), 4.72 (d, J=3 Hz, 1H), 4.16-4.13 (m, 1H), 3.81 (s, 3H), 3.71-3.77 (m, 2H), 2.65-2.52 (m, 2H), 1.97-1.92 (m, 1H), 1.72-1.60 (m, 1H), 0.93 (s, 9H), 0.05 (s, 3H), −0.13 (s, 3H).

Herkunft & Nachweise