rac-3,4-dihydro-2,5,7,8-tetramethyl-2-(2-propenyl)-6-(phenylmethoxy)-2H-1-benzopyran → (6-Benzyloxy-2,5,7,8-tetramethylchroman-2-yl)acetaldehyde

HRID 580375ノート

反応式

HRID 580375 の反応式
O=[O+][O-].[O:4]=O.[CH3:6][C:7]1([CH2:28][CH:29]=C)[CH2:12][CH2:11][C:10]2[C:13]([CH3:27])=[C:14]([O:19][CH2:20][C:21]3[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=3)[C:15]([CH3:18])=[C:16]([CH3:17])[C:9]=2[O:8]1>CO>[CH3:6][C:7]1([CH2:28][CH:29]=[O:4])[CH2:12][CH2:11][C:10]2[C:13]([CH3:27])=[C:14]([O:19][CH2:20][C:21]3[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=3)[C:15]([CH3:18])=[C:16]([CH3:17])[C:9]=2[O:8]1

参加物

4

反応物 2

HCID 14210609rac-3,4-dihydro-2,5,7,8-tetramethyl-2-(2-propenyl)-6-(phenylmethoxy)-2H-1-benzopyranHCID 131711318Oxygen ozone

生成物 1

HCID 13422213(6-Benzyloxy-2,5,7,8-tetramethylchroman-2-yl)acetaldehyde

試薬・触媒・溶媒 1

HCID 887Methanol溶媒

反応条件

温度
-78 °C

実験手順

An ozone-oxygen gas mixture is passed into a solution of 0.67 g (2 mmoles) of rac-3,4-dihydro-2,5,7,8-tetramethyl-2-(2-propenyl)-6-(phenylmethoxy)-2H-1-benzopyran in 100 ml of methanol, with stirring, at -78° C. After the starting olefin has been consumed, the ozone flow is stopped and the solution is treated with excess dimethyl sulfide and allowed to warm to room temperature. The solution is concentrated in vacuo. The residue is chromatographed on silica gel giving rac-3,4-dihydro-2,5,7,8-tetramethyl-6-(phenylmethoxy)-2H-1-benzopyran-2-acetaldehyde, which can be converted to Vitamin E by the procedures in Helv. Chim. Acta set forth in Example 8.

後処理

  1. customAfter the starting olefin has been consumed
  2. additionthe solution is treated with excess dimethyl sulfide
  3. temperatureto warm to room temperature
  4. concentrationThe solution is concentrated in vacuo
  5. customThe residue is chromatographed on silica gel

出典と根拠

ORDレコード
ord-95465a65c4164dbdb912a878af53938e
出典データセット
uspto-grants-1988_06
特許番号
US04752646

反応ノート

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