Reaction Steps
TMS-diazomethane (2.0 M in ether, 0.0061 mL, 0.012 mmol) was added to a solution of (3R,6R)-6-benzyl-7-((4S,7S,10aS)-7-(methoxycarbonyl)-5-oxooctahydro-2H-pyrido[2,1-b][1,3]thiazepin-4-ylamino)-3-((4S,7S,10aS)-7-(methoxycarbonyl)-5-oxooctahydro-2H-pyrido[2,1-b][1,3]thiazepin-4-ylcarbamoyl)-7-oxoheptanoic acid (5.4 mg, 7.0 mmol) in DCM (0.06 mL) and MeOH (0.0062 mL). Gas evolution occurred. The reaction was stirred at rt for 1 hr. The reaction mixture was concentrated and triturated with hexanes. The solid was dried over vacuum to give methyl (4S,7S,10aS)-4-(((2R,5R)-5-benzyl-6-(((4S,7S,10aS)-7-(methoxycarbonyl)-5-oxooctahydro-7H-pyrido[2,1-b][1,3]thiazepin-4-yl)amino)-2-(2-methoxy-2-oxoethyl)-6-oxohexanoyl)amino)-5-oxooctahydro-7H-pyrido[2,1-b][1,3]thiazepine-7-carboxylate (5.0 mg, 0.0063 mmol, 91% yield) as a white solid. Anal. Calcd. for C38H52N4O10S2 m/z 788.7. found: 789.2 (M+H)+; 1H NMR (400 MHz, CDCl3) δ ppm 7.32 (1H, d), 7.25-7.21 (2H, m), 7.19-7.11 (3H, m), 7.00 (1H, d), 5.39 (1H, t, J=4.7 Hz), 5.36 (1H, t, J=4.7 Hz), 5.21-5.16 (1H, m), 5.16-5.12 (1H, m), 5.10-4.98 (2H, m), 3.72 (3H, s), 3.69 (3H, s), 3.65 (3H, s), 3.28-3.10 (2H, m), 2.98-2.81 (3H, m), 2.77-2.62 (3H, m), 2.47-2.37 (3H, m), 2.34 (1H, dd, J=15.7, 3.6 Hz), 2.27-2.19 (1H, m), 2.08-1.95 (4H, m), 1.88 (1H, ddd, J=10.9, 7.0, 3.6 Hz), 1.76-1.47 (12H, m).
