1a,7b-dihydro-2,2-dimethyl-7b-(2-pyridyl)-2H-oxireno[c][1]benzopyran-6-carbonitrile → rac-cis-3,4-dihydro-3-hydroxy-2,2-dimethyl-4-(2-pyridyl)-2H-1-benzopyran-6-carbonitrile

HRID 1073946Notes

Reaction equation

HRID 1073946 reaction equation
[CH3:1][C:2]1([CH3:21])[CH:7]2[O:8][C:6]2([C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][N:10]=2)[C:5]2[CH:15]=[C:16]([C:19]#[N:20])[CH:17]=[CH:18][C:4]=2[O:3]1>C(O)C.[Pd]>[OH:8][C@H:7]1[C@@H:6]([C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][N:10]=2)[C:5]2[CH:15]=[C:16]([C:19]#[N:20])[CH:17]=[CH:18][C:4]=2[O:3][C:2]1([CH3:21])[CH3:1].[OH:8][C@H:7]1[C@H:6]([C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][N:10]=2)[C:5]2[CH:15]=[C:16]([C:19]#[N:20])[CH:17]=[CH:18][C:4]=2[O:3][C:2]1([CH3:21])[CH3:1]

Participants

5

Reactant 1

HCID 198956531a,7b-dihydro-2,2-dimethyl-7b-(2-pyridyl)-2H-oxireno[c][1]benzopyran-6-carbonitrile

Product 2

HCID 15038906rac-cis-3,4-dihydro-3-hydroxy-2,2-dimethyl-4-(2-pyridyl)-2H-1-benzopyran-6-carbonitrileHCID 131716718rac-trans-3,4-dihydro-3-hydroxy-2,2-dimethyl-4-(2-pyridyl)-2H-1-benzopyran-6-carbonitrile

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 702EthanolSolvent

Procedure

646 mg of 1a,7b-dihydro-2,2-dimethyl-7b-(2-pyridyl)-2H-oxireno[c][1]benzopyran-6-carbonitrile were dissolved in 100 ml of ethanol and 100 mg of 10% palladium-on-charcoal were added. The mixture was shaken under a hydrogen atmosphere overnight and then filtered. The filtrate was evaporated and the resulting oil was chromatographed twice on silica gel, with the elution being carried out initially using ethyl acetate/petroleum ether (1:3) and then 1% to 2% (v/v) methanol/dichloromethane. There were obtained 66 mg of rac-cis-3,4-dihydro-3-hydroxy-2,2-dimethyl-4-(2-pyridyl)-2H-1-benzopyran-6-carbonitrile of melting point 186°-188° C. (from acetonitrile) and 340 mg of rac-trans-3,4-dihydro-3-hydroxy-2,2-dimethyl-4-(2-pyridyl)-2H-1-benzopyran-6-carbonitrile of melting point 175°-176° C. (from t-butyl methyl ether).

Workup

  1. filtrationfiltered
  2. customThe filtrate was evaporated
  3. customthe resulting oil was chromatographed twice on silica gel, with the elution

Sources & evidence

ORD record
ord-a6321974f8db48e7aece816c3fe05060
Source dataset
uspto-grants-1990_11
Patent number
US04971982

Reaction notes

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