Trifluoroacetic acid → (+)-12-Oxocalanolide A

HRID 1637978

反応式

HRID 1637978 の反応式
[CH3:1][C:2]1([CH3:25])[O:7][C:6]2C3C(CCC)=[CH:12][C:11](=[O:17])[O:10][C:9]=3[C:18]([C:21](=[O:24])[CH2:22][CH3:23])=[C:19]([OH:20])[C:5]=2[CH:4]=[CH:3]1.[CH3:26][C:27]1C=CC(S([O-])(=O)=O)=CC=1.[CH:37]1[CH:42]=[CH:41][NH+]=[CH:39][CH:38]=1.CC1OC(C)OC(C)O1.C(C(O)=O)(F)(F)F.C([O-])(O)=O.[Na+]>ClCCCl>[CH3:39][CH2:38][CH2:37][C:42]1[C:41]2[C:6]3[O:7][C:2]([CH3:25])([CH3:1])[CH:3]=[CH:4][C:5]=3[C:19]3[O:20][C@H:26]([CH3:27])[C@@H:22]([CH3:23])[C:21](=[O:24])[C:18]=3[C:9]=2[O:10][C:11](=[O:17])[CH:12]=1

参加物

7

反応物 5

HCID 6422Trifluoroacetic acidHCID 31264Paraldehyde2 回HCID 466102Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1)2 回HCID 516892Sodium BicarbonateHCID 54948815-Hydroxy-2,2-dimethyl-6-propionyl-10-propyl-2H,8H-pyrano[2,3-f]chromen-8-one

生成物 1

HCID 463613(+)-12-Oxocalanolide A収率 27.1%

試薬・触媒・溶媒 1

HCID 111,2-Dichloroethane溶媒

実験手順

To a stirring solution of chromene 4 (350 mg, 1.0 mmol) and PPTS (250 mg, 1.0 mmol) in 1,2-dichloroethane (2 mL) at ambient temperature under N2 was added 3 mL paraldehyde (22.5 mmol). The resulting mixture was refluxed for 7 h. Then, CF3CO2H (1 mL), an additional equivalent of PPTS and 1 mL of paraldehyde were added; the mixture was refluxed overnight. The reaction mixture was neutralized with saturated aqueous NaHCO3 and extracted with ethyl acetate (50 mL×3). The crude product obtained by evaporation under reduced pressure was washed with hexane. The residue was purified by column chromatography eluting with ethyl acetate/hexane (1:2) to afford 100 mg (27% yield) of chromanone 7 and 30 mg (8% yield) of 7a. Chromanone 7 (10,11-trans-dihydro-6,6,10,11-tetramethyl-4-propyl-2H,6H,12H-benzo[1,2-b:3,4-b':5,6-b"] tripyran-2,12-dione) obtained by this method was identical with an authentic sample by comparison of TLC, HPLC and spectroscopic data.

後処理

  1. temperatureThe resulting mixture was refluxed for 7 h
  2. temperaturethe mixture was refluxed overnight
  3. extractionextracted with ethyl acetate (50 mL×3)
  4. customThe crude product obtained by evaporation under reduced pressure
  5. washwas washed with hexane
  6. customThe residue was purified by column chromatography
  7. washeluting with ethyl acetate/hexane (1:2)

出典と根拠

ORDレコード
ord-1346b91033bb4b0390938691d04fd7b1
出典データセット
uspto-grants-2000_03
特許番号
US06043271

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