C([S:4][CH2:5][CH:6]1[CH2:10][S:9][C:8]2([CH2:14][CH2:13][CH:12]([CH2:15][C:16]([O:18][CH2:19][CH3:20])=[O:17])[CH2:11]2)[S:7]1)(=O)C.[O-]CC.[Na+].OS([O-])(=O)=O.[K+]>C(O)C>[SH:4][CH2:5][CH:6]1[CH2:10][S:9][C:8]2([CH2:14][CH2:13][CH:12]([CH2:15][C:16]([O:18][CH2:19][CH3:20])=[O:17])[CH2:11]2)[S:7]1A solution of the product of Example F and sodium ethoxide (prepared from 350 mg of sodium metal) in absolute ethanol (40 ml) was stirred for 1 hr under nitrogen. The reaction mixture was poured into 200 ml of 0.5N KHSO4 and extracted with ethyl acetate. After drying the organic phase over sodium sulfate, the solvent was removed on the rotary evaporator and the residue was chromatographed on silica gel using 5% ethyl acetate/hexane to give 2.1 g of the titled compound.
Wird geladen…