反应详情

Pyridinium chlorochromate (PCC) (13.6 mg, 0.06 mmol, 4.5 eq.) was added to a solution of Auristatin E (29a) (10 mg, 0.014 mmol, 1 eq.) in CH2Cl2 (2 mL) and pyridine (50 μL). The reaction mixture was stirred at room temperature for 3 h. HPLC analysis of the reaction mixture showed complete conversion of the 10.2 min peak into a new 11.3 min peak with different UV spectrum (max 245 nm, shoulder 280 nm). The product was purified by flash chromatography on a silica gel column (120×12 mm) in a step gradient of MeOH in CH2Cl2 from 0 to 10%. After concentration in vacuum, the residue was triturated with hexane to give white solid. Yield 35: 6.4 mg (64%); Rf 0.3 (CH2Cl2/MeOH, 10/1); UV λmax 215, 245 nm. HRMS m/z: found 730.5119 [M+H]+. C40H68N5O7 requires 730.5108.

1. customconversion of the 10.2 min peak
2. custominto a new 11.3 min
3. customThe product was purified by flash chromatography on a silica gel column (120×12 mm) in a step gradient of MeOH in CH2Cl2 from 0 to 10%
4. concentrationAfter concentration in vacuum
5. customthe residue was triturated with hexane
6. customto give white solid