[Si:1]([O:8][CH2:9][CH:10]([C:12]1[CH:13]=[C:14]([NH:18][C:19](=[O:28])[O:20][CH2:21][C:22]2[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=2)[CH:15]=[CH:16][CH:17]=1)[OH:11])([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].C(N(CC)CC)C.[S:36](Cl)([CH3:39])(=[O:38])=[O:37]>C(Cl)Cl>[CH3:39][S:36]([O:11][CH:10]([C:12]1[CH:17]=[CH:16][CH:15]=[C:14]([NH:18][C:19]([O:20][CH2:21][C:22]2[CH:23]=[CH:24][CH:25]=[CH:26][CH:27]=2)=[O:28])[CH:13]=1)[CH2:9][O:8][Si:1]([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2])(=[O:38])=[O:37]Benzyl 3-(2-(tert-butyldimethylsilyloxy)-1-hydroxyethyl)phenylcarbamate (4 g) was dissolved in dry DCM (80 mL) and cooled to 0° C. under an argon atmosphere. Triethylamine (5 g) was added, followed by mesyl chloride (3.42 g) added drop-wise over a period of 2 hours. The reaction temp was maintained at 0° C. for further 2 hours. The reaction was quenched by addition of water, extracted into DCM and concentrated under vacuum at a temperature below 25° C. The crude product (3.5 g) was unstable and was used for next step as soon as possible.
Wird geladen…