Boron trifluoride etherate → 17-Ethyl-1-hydroxy-12-[2'-(4"-hydroxy-3"-ethoxycyclohexyl)-1'-methylvinyl]-23,25-dimethoxy-13,19,21,27-tetramethyl-11,28-dioxa-4-azatricyclo[22.3.1.04,9]octacos-18-ene-2,3,10,16-tetraone

Beteiligte Stoffe

Reaktionsschritte

To a solution of 17-ethyl-1-hydroxy-12-[2'-(3",4"-dihydroxycyclohexyl)-1'-methylvinyl]-23,25-di-methoxy-13,19,21,27-tetramethyl-11,28-dioxa-4-azatricyclo[22.3.1.04,9 ]octacos-18-ene-2,3,10,16-tetraone (200 mg, Example 38) in ether (6 ml) is added borontrifluoride etherate (10 μl) followed by freshly prepared diazoethane (100 fold excess). The mixture is stirred at room temperature for 15 min and quenched with sat'd aqueous sodium bicarbonate solution. The organic layer is separated, washed (sat'd aqueous NaCl) and dried over anhydrous magnesium sulfate. Removal of solvent followed by preparative tlc on silica to separate the regioisomers gives the title compound.

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