Acetic Acid → (S)-2-ethynyl-3,4-dihydro-2,5,7,8-tetramethyl-2H-1-benzopyran-6-ol

HRID 1199193

反応式

HRID 1199193 の反応式
C(O[C@@:5]([CH3:21])([C:19]#[CH:20])[CH2:6][CH2:7][C:8]1[C:9](=[O:18])[C:10]([CH3:17])=[C:11]([CH3:16])[C:12](=[O:15])[C:13]=1[CH3:14])(=O)C.C(O)(=O)C>C(Cl)Cl.[Zn]>[C:19]([C@:5]1([CH3:21])[CH2:6][CH2:7][C:8]2[C:13]([CH3:14])=[C:12]([OH:15])[C:11]([CH3:16])=[C:10]([CH3:17])[C:9]=2[O:18]1)#[CH:20]

参加物

5

反応条件

温度
4 °C

実験手順

A solution of 285 mg (0.99 mmol) of (R)-2-[3-(acetyloxy) 3-methyl-4-pentynyl]-3,5,6-trimethyl-2,5-cyclohexadiene-1,4-dione in 4 mL of CH2Cl2 was stirred with 250 mg of Zn dust, and 250 mg of glacial acetic acid. The reaction mixture was stirred at 4° C. under argon for 50 min. then filtered. It was worked up with CH2Cl2 as described above. The crude hydroquinone acetate was taken into 6 mL of CH2Cl2 and treated with 20 mg of AgClO4 ·H2O as described above to give 124 mg of crude product after workup, and purification by flash chromatography. Crystallization of this material from toluene-hexane (1:1) at -15° C. gave 57 mg of (S)-2-ethynyl-3,4-dihydro-2,5,7,8-tetramethyl-2H-1-benzopyran-6-ol: [α]D25 +20.20°, (c 1.3, CHCl3).

後処理

  1. filtrationthen filtered
  2. additiontreated with 20 mg of AgClO4 ·H2O
  3. customto give 124 mg of crude product
  4. customafter workup, and purification by flash chromatography
  5. customCrystallization of this material from toluene-hexane (1:1) at -15° C.

出典と根拠

ORDレコード
ord-f2d5e3af4e014a908249a6be66c0cf40
出典データセット
uspto-grants-1990_02
特許番号
US04898953

関連ノート

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