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

HRID 1195481Notes

Reaction equation

HRID 1195481 reaction equation
C(O[CH2:10]/[CH:11]=[C:12](\[CH3:26])/[CH2:13][CH2:14][C:15]1[C:20]([CH3:21])=[C:19]([OH:22])[C:18]([CH3:23])=[C:17]([CH3:24])[C:16]=1[OH:25])(=O)C1C=CC=CC=1>C1COCC1>[CH3:26][C@@:12]1([CH:11]=[CH2:10])[CH2:13][CH2:14][C:15]2[C:20]([CH3:21])=[C:19]([OH:22])[C:18]([CH3:23])=[C:17]([CH3:24])[C:16]=2[O:25]1

Participants

3

Reactant 1

HCID 86745748(E)-5-(2,5-dihydroxy-3,4,6-trimethylphenyl)-3-methyl-2-pentenyl benzoate

Product 1

HCID 22843764(S)-3,4-dihydro-2,5,7,8-tetramethyl-2-vinyl-2H-[1]-benzopyran-6-olYield 56%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of 106 mg (0.3 mmol) of (E)-5-(2,5-dihydroxy-3,4,6-trimethylphenyl)-3-methyl-2-pentenyl benzoate, 5 mg (3%) of (R)-6,6'-dimethyl-2,2'-bis-(diphenylphosphino)-1,1'-biphenyl and 1.7 mg (1.5%) of π-allylpalladium chloride dimer in 5 ml of THF was heated to 70° C. for 24 hours. After cooling the solvent was removed and the residue was Purified as described in Experiment 1, yielding 39 mg of (S)-3,4-dihydro-2,5,7,8-tetramethyl-2-vinyl-2H-[1]-benzopyran-6-ol. O.P. 56%.

Workup

  1. temperatureAfter cooling the solvent
  2. customwas removed
  3. customthe residue was Purified

Sources & evidence

ORD record
ord-f30d1f7b8b3542f79894234df251369c
Source dataset
uspto-grants-1992_05
Patent number
US05110955

Reaction notes

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