反应详情

A solution of DMSO (14.6 g, 187 mmol) in dichloromethane (300 mL) was treated with oxalyl dichloride (17.7 g, 140 mmol) at −78° C. for 1 hour, then a solution of ((3aR,5R,6S,7R,7aR)-6,7-bis(benzyloxy)-2-(dimethylamino)-5,6,7,7a-tetrahydro-3aH-pyrano[3,2-d]thiazol-5-yl)methanol (10 g, 23 mmol) in dichloromethane (30 mL) was added slowly. The resulted solution was kept for 4 hours at −20° C., followed by the addition of triethylamine (28.3 g, 280 mmol) at −78° C. After additional 1 hour at −50° C., the reaction was quenched by water (300 mL) and extracted with dichloromethane (2×200 mL). The organic layers combined, washed with brine (3×100 mL) and dried over anhydrous sodium sulfate. After filtration, the filtrates were concentrated under vacuum to give a residue, which was purified by a silica gel column, eluted with 20% ethyl acetate in dichloromethane to give compound 95 as a yellow syrup (8.1 g, 80%). (ES, m/z): [M+H]+ 426.7; 1H NMR (300 MHz, CDCl3) δ 9.62 (s, 1H), 7.28-7.39 (m, 10H), 6.27-6.34 (m, 1H), 4.41-4.84 (m, 6H), 4.10-4.17 (m, 1H), 3.86-3.94 (m, 1H), 3.02 (s, 6H).

1. waitAfter additional 1 hour at −50° C.
2. customthe reaction was quenched by water (300 mL)
3. extractionextracted with dichloromethane (2×200 mL)
4. washwashed with brine (3×100 mL)
5. dry with materialdried over anhydrous sodium sulfate
6. filtrationAfter filtration
7. concentrationthe filtrates were concentrated under vacuum
8. customto give a residue, which
9. customwas purified by a silica gel column
10. washeluted with 20% ethyl acetate in dichloromethane