반응 #714366

반응 방정식

(5R)-(9H-fluoren-9-yl)methyl 5-((benzyloxy)(tert-butoxycarbonyl)amino)-3-(((tert-butyldimethylsilyl)oxy)methyl)-2-cyano-5,6-dihydropyridine-1(2H)-carboxylate

Intermediate 160

(5R)-(9H-fluoren-9-yl)methyl 5-((benzyloxy)(tert-butoxycarbonyl)amino)-3-(((tert-butyldimethylsilyl)oxy)methyl)-2-cyano-5,6-dihydropyridine-1(2H)-carboxylate

acetaldehyde oxime

→

title compound

수율 89.1%

(5R)-(9H-fluoren-9-yl)methyl 5-((benzyloxy)(tert-butoxycarbonyl)amino)-3-(((tert-butyldimethylsilyl)oxy)methyl)-2-carbamoyl-5,6-dihydropyridine-1(2H)-carboxylate

수율 89.1%

용매

MeOH

반응 조건

후처리

1. 1
   여과The mixture was filtered
2. 2
   기타evaporated
3. 3
   기타The residue was purified on silica gel column (0-60%, EtOAc/hexanes)

실험 절차

A mixture of (5R)-(9H-fluoren-9-yl)methyl 5-((benzyloxy)(tert-butoxycarbonyl)amino)-3-(((tert-butyldimethylsilyl)oxy)methyl)-2-cyano-5,6-dihydropyridine-1(2H)-carboxylate (Intermediate 160, 1.3 g, 1.87 mmol), acetaldehyde oxime (0.569 mL, 9.34 mmol) and newly activated copper(II) chloride on 4 Å MS (187 mg, 0.15 mmol) (used 100 mg CuCl2/mol sieves per 1 mmol substrate) in MeOH (5 mL) was stirred under nitrogen at 65° C. for 6 h. The mixture was filtered and evaporated. The residue was purified on silica gel column (0-60%, EtOAc/hexanes). The two diastereomers were combined together to afford the title compound (1.190 g, 89%) as a pale yellow foamy solid.

출처