[Si:1]([O:8][CH2:9][C:10]([C:12]1[CH:17]=[CH:16][CH:15]=[C:14]([F:18])[CH:13]=1)=O)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].[CH3:19][C:20]([S@:23]([NH2:25])=[O:24])([CH3:22])[CH3:21].[NH4+].[Cl-]>C1COCC1>[Si:1]([O:8][CH2:9]/[C:10](=[N:25]/[S@@:23]([C:20]([CH3:22])([CH3:21])[CH3:19])=[O:24])/[C:12]1[CH:17]=[CH:16][CH:15]=[C:14]([F:18])[CH:13]=1)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2]To a mixture of 58a (11.3 g, 42.1 mmol) and (R)-2-methylpropane-2-sulfinamide (6.60 g, 54.7 mmol) in THF (200 mL) at RT was added Ti(Oi-Pr)4 (29.9 g, 105 mmol). The reaction mixture was heated to reflux under N2 overnight. The mixture was cooled then treated with saturated NH4Cl (5.0 mL), and the insoluble material was filtered. The filtrate was dried (Na2SO4), filtered and concentrated in vacuo. The residue was purified by SiO2 chromatography eluting with petroleum ether/EtOAc gradient (60:1 to 20:1) to afford 7.6 g (49%) of (R,E)-N-(2-(tert-butyldimethylsilyloxy)-1-(3-fluorophenyl)ethylidene)-2-methylpropane-2-sulfinamide (58b) as yellow oil. LCMS (ESI) m/z: 372.2 [M+H]+.
読み込み中…