N-bromobutanimide → HCID 86701099, compound

Participants

Reaction Steps

To a mixture of tert-butyl (5R,6S,7R)-6,7-bis(4-methoxybenzyloxy)-5-(hydroxymethyl)-5,6,7,7a-tetrahydro-3aH-pyrano[3,2-d]thiazol-2-yl(propyl)carbamate (2 g, 3.32 mmol), KHCO3 (1.49 bg, 15 mmol), TBAB (53 mg, 0.16 mmol) and TEMPO (26 mg, 0.17 mmol) in dichloromethane (60 mL) and H2O (12 mL) was added NBS (592 mg, 3.33 mmol) at 15° C. After stirred for 30 min, the reaction mixture was quenched by saturated Na2SO3 (10 mL). The organic layer was dried over anhydrous magnesium sulfate and condensed to provide a residue, which was purified by silica gel column, eluted with 20-30% AcOEt in dichloromethane to give compound 20 as a yellow syrup (1.2 g, purity 60%). (ES, m/z): [M+H]+ 601.1. 1H NMR (300 MHz, CDCl3) δ 9.61 (s, 1H), 7.23-7.28 (m, 4H), 6.82-6.86 (m, 4H), 6.19-6.21 (d, J=6.9 Hz, 1H), 4.60-4.67 (m, 2H), 4.41-4.55 (m, 3H), 4.02-4.03 (m, 1H), 3.88-3.93 (m, 1H), 3.68-3.81 (m, 9H), 1.46-1.53 (m, 11H), 0.83-0.86 (t, J=7.5 Hz, 3H).

Provenance & Evidence