Acetic Anhydride → 4-Acetoxy-5-allyl-1,3-dihydro-6-methoxy-7-methyl-3-oxoisobenzofuran

HRID 1781562Notes

Reaction equation

HRID 1781562 reaction equation
[CH2:1]([C:4]1[C:5]([O:17][Si](C(C)(C)C)(C)C)=[C:6]2[C:10](=[C:11]([CH3:15])[C:12]=1[O:13][CH3:14])[CH2:9][O:8][C:7]2=[O:16])[CH:2]=[CH2:3].[C:25](OC(=O)C)(=[O:27])[CH3:26]>C(O)(=O)C>[C:25]([O:17][C:5]1[C:4]([CH2:1][CH:2]=[CH2:3])=[C:12]([O:13][CH3:14])[C:11]([CH3:15])=[C:10]2[C:6]=1[C:7](=[O:16])[O:8][CH2:9]2)(=[O:27])[CH3:26]

Participants

4

Reactant 2

HCID 7918Acetic AnhydrideHCID 100663665-Allyl-4-tert-butyldimethylsilyloxy-1,3-dihydro-6-methoxy-7-methyl-3-oxoisobenzofuran

Product 1

HCID 190463174-Acetoxy-5-allyl-1,3-dihydro-6-methoxy-7-methyl-3-oxoisobenzofuran

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

A solution of 5-allyl-4-tert-butyldimethylsilyloxy-1,3-dihydro -6-methoxy-7-methyl-3-oxoisobenzofuran [(J. W. Patterson and G. Huang, Chemical Communications, 1579 (1991)] (7.5 g) in acetic acid (95 ml) and acetic anhydride (95 ml) was refluxed for 18 hours, then cooled and poured into ice water. The solution was extracted with ethyl acetate, and the extract washed with dilute aqueous sodium bicarbonate, followed by water, then dried and evaporated. The residue was chromatographed on silica gel, eluting with 7:3 hexane:ethyl acetate, to give 4-acetoxy-5-allyl -1,3-dihydro-6-methoxy-7-methyl-3-oxoisobenzofuran, mp 101°-102° C.

Workup

  1. temperaturecooled
  2. extractionThe solution was extracted with ethyl acetate
  3. washthe extract washed with dilute aqueous sodium bicarbonate
  4. customdried
  5. customevaporated
  6. customThe residue was chromatographed on silica gel
  7. washeluting with 7:3 hexane

Sources & evidence

ORD record
ord-7820518b8590443d8b86b8ccf4ea84e0
Source dataset
uspto-grants-1997_05
Patent number
US05633279

Reaction notes

Loading…