Ethylene Glycol → Methyl 8-(4-bromophenyl)-1,4-dioxaspiro[4.5]decane-8-carboxylate

反応式

[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2([C:15]([O:17][CH3:18])=[O:16])[CH2:13][CH2:12][C:11](=[O:14])[CH2:10][CH2:9]2)=[CH:4][CH:3]=1.[CH2:19](O)[CH2:20][OH:21]>C1(C)C=CC(S(O)(=O)=O)=CC=1.C1(C)C=CC=CC=1>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([C:8]2([C:15]([O:17][CH3:18])=[O:16])[CH2:9][CH2:10][C:11]3([O:21][CH2:20][CH2:19][O:14]3)[CH2:12][CH2:13]2)=[CH:6][CH:7]=1

参加物

実験手順

To a round bottom flask containing methyl 1-(4-bromophenyl)-4-oxocyclohexanecarboxylate (4.64 g, 14.91 mmol) was added toluene (33 ml), ethylene glycol (8.32 ml, 149 mmol) and p-toluenesulfonic acid (85 mg, 0.45 mmol) at room temperature. The mixture was heated to 80 C. for 2 hours. The content was then cooled to room temperature and quenched with a saturated solution of sodium bicarbonate. The organic portion was washed with saturated sodium bicarbonate and the aqueous portion extracted with MTBE twice. The combined organic portion was dried over sodium sulfate and concentrated to afford a crude oil. Column purification afforded the title compound as viscous oil (5.30 g, quantitative yield). LC/MS, ESI-MS(+): 357.1, RT: 1.38 (Condition E).