Dibromomethane → (S)-2-methyl-4-methylidene-3-(2-propynyl)-1-tert-butyldimethylsilyloxycyclopent-2-ene

HRID 1078997ノート

反応式

HRID 1078997 の反応式
BrCBr.O1CCC[CH2:5]1.[Si:9]([O:16][C@H:17]1[CH2:21][C:20](=O)[C:19]([CH2:23][C:24]#[CH:25])=[C:18]1[CH3:26])([C:12]([CH3:15])([CH3:14])[CH3:13])([CH3:11])[CH3:10].C(=O)(O)[O-].[Na+]>ClCCl.[Zn].[Ti](Cl)(Cl)(Cl)Cl.O.CCCCCC>[CH3:26][C:18]1[C@@H:17]([O:16][Si:9]([C:12]([CH3:15])([CH3:14])[CH3:13])([CH3:11])[CH3:10])[CH2:21][C:20](=[CH2:5])[C:19]=1[CH2:23][C:24]#[CH:25]

参加物

10

反応物 4

HCID 3024DibromomethaneHCID 8028Tetrahydrofuran2 回HCID 516892Sodium BicarbonateHCID 11043662(S)-4-tert-butyldimethylsilyloxy-3-methyl-2-(2-propynyl)cyclopent-2-ene-1-one

生成物 1

HCID 11821434(S)-2-methyl-4-methylidene-3-(2-propynyl)-1-tert-butyldimethylsilyloxycyclopent-2-ene収率 68.7%

試薬・触媒・溶媒 5

HCID 23994Zinc触媒HCID 24193Titanium Tetrachloride触媒HCID 962Water溶媒HCID 6344Dichloromethane溶媒2 回HCID 8058Hexane溶媒

実験手順

1H-NMR (solvent: CDCl3, internal standard: TMS) δ value (ppm): 4.69(brd, 1H), 3.11(ABq, 2H), 2.74(dd, 1H), 2.28(dd, 1H), 2.16(s, 3H), 1.96(t, 1H), 0.92(s, 9H), 0.15(s, 3H), 0.12(s, 3H). 2 Dibromomethane (13.04 g) and zinc dust (14.71 g) were added to tetrahydrofuran (120ml), and the resulting mixture was cooled to 0°~5° C. A dichloromethane solution (50 ml) of 1M titanium tetrachloride was added to the tetrahydrofuran solution over about 10 min, and the resulting mixture was allowed to react for 3 days at 0°~5° C. Then a solution of (S)-4-tert-butyldimethylsilyloxy-3-methyl-2-(2-propynyl)cyclopent-2-ene-1-one (13.22 g) in dichloromethane (50 ml) was added at 0°~5° C. over about 10 min. After the reaction was continued for 2 hours at the same temperature, hexane (200 ml) and then a slurry consisting of sodium bicarbonate (75 g) and water (40 ml) were added After stirring for 2 hours at 0°~5° C., the organic layer was separated by decantation. The obtained residue was extracted three times with n-hexane (200 ml). The combined organic layer was washed with saturated aqueous sodium bicarbonate solution, and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure, and the resultant residue was subjected to silica gel column chromatography (eluent; n-hexane: ethyl acetate=50:1) to afford the desired product, (S)-2-methyl-4-methylidene-3-(2-propynyl)-1-tert-butyldimethylsilyloxycyclopent-2-ene (9.02 g, yield 68.7%) as a pale yellow oil.

後処理

  1. temperaturethe resulting mixture was cooled to 0°~5° C
  2. customto react for 3 days at 0°~5° C
  3. additionwere added
  4. customthe organic layer was separated by decantation
  5. extractionThe obtained residue was extracted three times with n-hexane (200 ml)
  6. washThe combined organic layer was washed with saturated aqueous sodium bicarbonate solution
  7. dry with materialdried over anhydrous sodium sulfate
  8. customThe solvent was evaporated under reduced pressure

出典と根拠

ORDレコード
ord-5540c9f93f7045289ad831cc82e1ba82
出典データセット
uspto-grants-1996_08
特許番号
US05550260

反応ノート

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