[O:1]1[C:5]2[CH:6]=[CH:7][C:8]([C:10]3[CH:18]=[CH:17][C:13]([C:14]([NH2:16])=[O:15])=[C:12]([F:19])[CH:11]=3)=[CH:9][C:4]=2[CH:3]=[CH:2]1.[Li]CCCC.[B:25]([O-])([O-:27])[O-:26]>C1COCC1>[C:14]([C:13]1[CH:17]=[CH:18][C:10]([C:8]2[CH:7]=[CH:6][C:5]3[O:1][C:2]([B:25]([OH:27])[OH:26])=[CH:3][C:4]=3[CH:9]=2)=[CH:11][C:12]=1[F:19])(=[O:15])[NH2:16]Intermediate 20 (100 mg 0.4 mmol) was dissolved in THF (10 ml) and this mixture was cooled to −78° C. under N2 atmosphere. n-BuLi (0.5 ml, 1.3 mmol) was added to the above mixture and stirred at same temperature for 20 mins Reaction mixture warmed to 0° C. and stirred for 2 hrs. After that trisopropyl borate (88 mg, 0.47 mmol) was added and stirred the reaction for 16 h at rt. Reaction mass quenched with 2N HCl worked it up (EtOAC/H2O) to afford the titled compound (110 mg) as a crude. It was used in the next step without further purification.
Wird geladen…
