반응 #999

ord-c3c99a608b9c4984be003f74893691b4

반응 방정식

O=C([O-])O.[Na+]
sodium bicarbonate
BrBr
Bromine
O=C1CCCCCC1
cycloheptanone
OCCO
ethylene glycol
BrC1CCCCCC12OCCO2
2-bromocycloheptanone ethylene ketal

반응 조건

상세 조건
See reaction.notes.procedure_details.

후처리

  1. 1
    추출extracted 3× with diethyl ether
  2. 2
    세척The combined organic layers were washed with brine
  3. 3
    건조dried over sodium sulfate
  4. 4
    여과filtered
  5. 5
    농축concentrated in vacuo

실험 절차

Bromine (44.8 g, 0.28 mol) was added dropwise to a stirred solution of cycloheptanone (28.5 g, 0.25 mol) in a 1:1 solution (300 mL) of ethylene glycol and tetrahydrofuran at room temperature. The mixture was stirred for 5 hours, then poured into aqueous sodium bicarbonate and extracted 3× with diethyl ether. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to give 2-bromocycloheptanone ethylene ketal (60 g). A mixture of this crude bromo ketal and a methanolic solution of sodium methoxide (250 mL, 25 wt. % solution) was heated at reflux overnight. The mixture was cooled to ambient temperature, poured into water, and extracted with hexanes. The organic layer was washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to afford 2-cycloheptenone ethylene ketal (39 g).

출처

DOI: 10.6084/m9.figshare.5104873.v1특허: US05723462uspto-grants-1998_03