Dimethylformamide → 4-Benzyloxy-6-methyl-2H-pyran-2-one

HRID 1252721ノート

反応式

HRID 1252721 の反応式
[H-].[Na+].[OH:3][C:4]1[CH:9]=[C:8]([CH3:10])[O:7][C:6](=[O:11])[CH:5]=1.CN(C=O)C.[CH2:17](Br)[C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1>O1CCCC1.[I-].C([N+](CCCC)(CCCC)CCCC)CCC.CN(P(N(C)C)(N(C)C)=O)C>[CH2:17]([O:3][C:4]1[CH:9]=[C:8]([CH3:10])[O:7][C:6](=[O:11])[CH:5]=1)[C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1

参加物

8

反応物 4

HCID 6228DimethylformamideHCID 7498Benzyl BromideHCID 24758Sodium hydrideHCID 546757574-Hydroxy-6-methyl-2-pyrone

生成物 1

HCID 27844494-Benzyloxy-6-methyl-2H-pyran-2-one収率 40%

試薬・触媒・溶媒 3

HCID 67553Tetrabutylammonium Iodide触媒HCID 8028Tetrahydrofuran溶媒HCID 12679Hexamethylphosphoramide溶媒

実験手順

Sodium hydride (2.2 gm, 50% oil, 0.0458 mol) was added portionwise to a solution of 4-hydroxy-6-methyl-2-pyrone (5 gm, 0.0396 mol) in anhydrous tetrahydrofuran. When the gas evolution ceased, anhydrous DMF (80 ml) was added, along with tetra-n-butylammonium iodide (1 gm). The solution was stirred at room temperature for 30 minutes. A solution of benzyl bromide (5.2 ml, 0.0425 mol) in HMPA (5 ml) was added. After 16 hours at room temperature, the volatile component was removed by evaporation. DMF was removed under high vacuum (1 mm Hg). The residual oil was partitioned between 10% HCl and ethyl acetate. The ethyl acetate layer was dried over magnesium sulphate and evaporated to an oil. This material was purified by flash column chromatography (Whatman LPS-II silica gel, elution gradient: 10-50% ethyl acetate:pet. ether 30-60; product Rf =0.4 at 30% ethyl acetate:pet. ether 30-60). The material was recrystallized from ether to give 4-benzyloxy- 6-methyl-2-pyrone (3.42 gm, 40% yield), m.p. 90°-91° C.; IR (KBr): 1740, 1575, 1650 cm-1, Anal. calcd. for C13H12O3 : C, 72.21, H, 5.59. Found: C, 72.31, H, 5.64.

後処理

  1. waitAfter 16 hours at room temperature
  2. customthe volatile component was removed by evaporation
  3. customDMF was removed under high vacuum (1 mm Hg)
  4. customThe residual oil was partitioned between 10% HCl and ethyl acetate
  5. dry with materialThe ethyl acetate layer was dried over magnesium sulphate
  6. customevaporated to an oil
  7. customThis material was purified by flash column chromatography (Whatman LPS-II silica gel, elution gradient: 10-50% ethyl acetate:pet. ether 30-60; product Rf =0.4 at 30% ethyl acetate:pet. ether 30-60)
  8. customThe material was recrystallized from ether

出典と根拠

ORDレコード
ord-15f8c3f4f6404bafb67bbf8aad03448f
出典データセット
uspto-grants-1988_05
特許番号
US04745116

反応ノート

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