Ammonium Chloride → (S)-3,4-dihydro-2,5,7,8-tetramethyl-2-vinyl-2H-[1]-benzopyran-6-ol

HRID 1195482Notes

Reaction equation

HRID 1195482 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.[H-].[Ca+2].[H-].[Cl-].[NH4+]>CS(C)=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

5

Reactant 3

HCID 25517Ammonium ChlorideHCID 3033859Calcium hydrideHCID 19819049(E)-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 67%

Reagents, catalysts & solvents 1

HCID 679Dimethyl SulfoxideSolvent

Procedure

A solution of 106 mg (0.36 mmol) of (E)-5-(2,5-dihydroxy-3,4,6-trimethylphenyl)-3-methyl-2-pentenyl acetate and 9 mg (3%) of [[(R)-6,6'-dimethyl-1,1'-biphenyl-2,2'-bis(diphenylphosphine)]-P,P'][(η-3)-2-propenyl]palladium perchlorate in 2 ml of DMSO was treated with 15 mg of calcium hydride and stirred at room temperature for three days. Thereafter, the mixture was poured into saturated ammonium chloride solution and extracted with ether. The combined extracts were washed with water and dried. The residue remaining after removal of the solvent was purified as described in Experiment 1, yielding 56 mg of (S)-3,4-dihydro-2,5,7,8-tetramethyl-2-vinyl-2H-[1]-benzopyran-6-ol. O.P. 33%.

Workup

  1. extractionextracted with ether
  2. washThe combined extracts were washed with water
  3. customdried
  4. customafter removal of the solvent
  5. customwas purified

Sources & evidence

ORD record
ord-c164f9981cbf4bf89597af5800d473d6
Source dataset
uspto-grants-1992_05
Patent number
US05110955

Reaction notes

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