(Z)-5-(2,5-dihydroxy-3,4,6-trimethylphenyl)-3-methyl-2-pentenyl acetate → (S)-3,4-dihydro-2,5,7,8-tetramethyl-2-vinyl-2H-[1]-benzopyran-6-ol

HRID 1195480Notes

Reaction equation

HRID 1195480 reaction equation
C(O[CH2:5]/[CH:6]=[C:7](/[CH3:21])\[CH2:8][CH2:9][C:10]1[C:15]([CH3:16])=[C:14]([OH:17])[C:13]([CH3:18])=[C:12]([CH3:19])[C:11]=1[OH:20])(=O)C>CS(C)=O.O>[CH3:21][C@@:7]1([CH:6]=[CH2:5])[CH2:8][CH2:9][C:10]2[C:15]([CH3:16])=[C:14]([OH:17])[C:13]([CH3:18])=[C:12]([CH3:19])[C:11]=2[O:20]1

Participants

4

Reactant 1

HCID 86745750(Z)-5-(2,5-dihydroxy-3,4,6-trimethylphenyl)-3-methyl-2-pentenyl acetate

Product 1

HCID 22843764(S)-3,4-dihydro-2,5,7,8-tetramethyl-2-vinyl-2H-[1]-benzopyran-6-olYield 86.1%

Reagents, catalysts & solvents 2

HCID 679Dimethyl SulfoxideSolventHCID 962WaterSolvent

Procedure

A solution of 125 mg (0.43 mmol) of (Z)-5-(2,5-dihydroxy-3,4,6-trimethylphenyl)-3-methyl-2-pentenyl acetate, 8 mg (3%) of (S)-2,2'-bis-(diphenylphosphino)-1,1'-binaphthalene and 2.3 mg (1.5%) of π-allylpalladium chloride dimer in DMSO (3 ml) was left at 60° C. for 17 hours. After cooling the mixture was diluted with water and extracted with ether. The extracts were washed with water, dried, concentrated and the residue was purified as in Experiment 1, yielding 86 mg of (S)-3,4-dihydro-2,5,7,8-tetramethyl-2-vinyl-2H-[1]-benzopyran-6-ol. O.P. 36%.

Workup

  1. temperatureAfter cooling the mixture
  2. extractionextracted with ether
  3. washThe extracts were washed with water
  4. customdried
  5. concentrationconcentrated
  6. customthe residue was purified as in Experiment 1

Sources & evidence

ORD record
ord-331d439b3ade4588b4a4e5069a25e3c4
Source dataset
uspto-grants-1992_05
Patent number
US05110955

Reaction notes

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