1,2-Dibromoethane → 2,3-Dihydro-1,4-benzoxathiin-6-ol

Reaktionsgleichung

Br[CH2:2][CH2:3]Br.C([O-])([O-])=O.[K+].[K+].[SH:11][C:12]1[CH:17]=[C:16]([OH:18])[CH:15]=[CH:14][C:13]=1[OH:19]>CC(C)=O>[O:19]1[C:13]2[CH:14]=[CH:15][C:16]([OH:18])=[CH:17][C:12]=2[S:11][CH2:3][CH2:2]1

Komponenten

Versuchsvorschrift

1,2-Dibromoethane (2.3 mL, 26.7 mmol) and K2CO3 (8.21 g, 59.4 mmol) were slurried in acetone (250 mL) and a solution of 2-sulfanyl-1,4-benzenediol (prepared according to J. Org. Chem. 1990, 55, 2736) (4.22 g, 29.7 mmol) in acetone (50 mL) was added over 4 h to the stirred mixture. Once the addition was complete stirring was continued for a further 10 h before the solvent was removed in vacuo. The residue was partitioned between water (50 mL) and EtOAc (50 mL), the aqueous layer was extracted with EtOAc (50 mL) and the combined organic layers were dried (MgSO4) and evaporated. Purification of the residue by column chromatography [SiO2; 9:1 (pentane/EtOAc)] gave the title compound (2.48 g, 55%) as a pale orange oil; δH (CDCl3, 400 MHz) 3.08 (2H, m), 4.31 (2H, m), 4.44 (1H, s), 6.42 (1H, d), 6.49 (1H, s), 6.66 (1H, d); MS m/z (ES−) 167 (M−H+).