[I:1][C:2]1[CH:15]=[CH:14][C:13]2[C:12]3[C:7](=[CH:8][C:9](I)=[CH:10][CH:11]=3)[CH2:6][CH2:5][C:4]=2[CH:3]=1.B(OC(C)C)(OC(C)C)[O:18]C(C)C.C([Li])CCC.Cl>C1COCC1.CCCCCC>[I:1][C:2]1[CH:3]=[C:4]2[C:13]([C:12]3[CH:11]=[CH:10][C:9]([OH:18])=[CH:8][C:7]=3[CH2:6][CH2:5]2)=[CH:14][CH:15]=18.8 g (20.4 mmol) of 2,7-diiodo-9,10-dihydrophenanthrene are dissolved in 250 ml of THF, and, after addition of 7.0 ml (30.5 mmol) of triisopropyl borate, 16.5 ml of a 15 percent soln. of n-butyllithium in hexane are added at −70° C. After 1 h, the batch is hydrolysed using 2 N hydrochloric acid and warmed to room temperature. The solution is extracted twice with MTB ether, dried over sodium sulfate, the solvent is removed in vacuo, and the resultant crude product is suspended in 80 ml of toluene and 30 ml of 2 N sodium hydroxide solution with vigorous stirring. After addition of 8 ml of 30% hydrogen peroxide, the batch is stirred at 30-40° C. for 30 min with gentle cooling, 200 ml of water are added, and the mixture is acidified using 2 N hydrochloric acid. The aqueous phase is separated off and extracted three times with ethyl acetate. The combined org. phases are washed with dil. ammonium iron(II) sulfate soln. and dried over sodium sulfate. The solvent is removed in vacuo, and the residue is filtered through silica gel with dichloromethane, giving 7-iodo-9,10-dihydrophenanthren-2-ol as colourless solid.
読み込み中…
