Acetic Anhydride → 9-Acetoxy-4,4-dimethyl-7-(1,2-dimethylheptyl)-1,2,3,4-tetrahydrocyclopenta[c][l] benzopyran

HRID 2072317Notes

Reaction equation

HRID 2072317 reaction equation
[CH3:1][C:2]1([CH3:25])[C:7]2[CH2:8][CH2:9][CH2:10][C:6]=2[C:5]2[C:11]([OH:24])=[CH:12][C:13]([CH:15]([CH3:23])[CH:16]([CH3:22])[CH2:17][CH2:18][CH2:19][CH2:20][CH3:21])=[CH:14][C:4]=2[O:3]1.[C:26](OC(=O)C)(=[O:28])[CH3:27]>N1C=CC=CC=1>[C:26]([O:24][C:11]1[C:5]2[C:6]3[CH2:10][CH2:9][CH2:8][C:7]=3[C:2]([CH3:1])([CH3:25])[O:3][C:4]=2[CH:14]=[C:13]([CH:15]([CH3:23])[CH:16]([CH3:22])[CH2:17][CH2:18][CH2:19][CH2:20][CH3:21])[CH:12]=1)(=[O:28])[CH3:27]

Participants

4

Reactant 2

HCID 7918Acetic AnhydrideHCID 215348Cyclopenta(c)(1)benzopyran-9-ol, 1,2,3,4-tetrahydro-4,4-dimethyl-7-(1,2-dimethylheptyl)-

Product 1

HCID 218539109-Acetoxy-4,4-dimethyl-7-(1,2-dimethylheptyl)-1,2,3,4-tetrahydrocyclopenta[c][l] benzopyran

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

A solution of 4,4-dimethyl-9-hydroxy-7-(1,2-dimethylheptyl)-1,2,3,4-tetrahydrocyclopenta[ c][l]benzopyran (6.85 g., 0.02 mole) and acetic anhydride (3.06 g., 0.03 mole) in 20 ml. of pyridine was warmed over a steam bath with stirring for 2 hours. The reaction mixture was allowed to cool to room temperature and the pyridine was removed by evaporation under reduced pressure. Water was added to the residue and this aqueous mixture was extracted with three portions of ether. The ether extracts were washed several times with water, 6N HCl, again with water, and dried over Na2SO4. Solvent evaporation in vacuo left 7.59 g. (99%) of crude acetate. The ir and nmr were in agreement with the proposed structure.

Workup

  1. customthe pyridine was removed by evaporation under reduced pressure
  2. additionWater was added to the residue
  3. extractionthis aqueous mixture was extracted with three portions of ether
  4. washThe ether extracts were washed several times with water, 6N HCl
  5. dry with materialagain with water, and dried over Na2SO4
  6. customSolvent evaporation in vacuo
  7. waitleft 7.59 g

Sources & evidence

ORD record
ord-cd0a699458314b2ba21c7bbbcea18164
Source dataset
uspto-grants-1977_09
Patent number
US04051152

Reaction notes

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