Reaktion #58695

Reaktionsgleichung

Pyridinium chlorochromate

Auristatin E

→

35

N,N-dimethyl-L-valyl-N-[(1S,2R)-4-[(2S)-2-[(1R,2R)-3-[[(1R)-2-oxo-1-methyl-2-phenylethyl]amino]-1-methoxy-2-methyl-3-oxopropyl]-1-pyrrolidinyl]-2-methoxy-1-[(1S)-1-methylpropyl]-4-oxobutyl]-N-methyl-L-valinamide

Lösungsmittel

CH2Cl2

pyridine

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeconversion of the 10.2 min peak
2. 2
   Sonstigeinto a new 11.3 min
3. 3
   SonstigeThe 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. 4
   EinengenAfter concentration in vacuum
5. 5
   Sonstigethe residue was triturated with hexane
6. 6
   Sonstigeto give white solid

Vorschrift

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.

Quelle