Phenol → 4,4-Dimethylchroman

HRID 1085017

Reaction equation

HRID 1085017 reaction equation
[C:1]1([OH:7])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.P([O-])([O-])(O[CH2:11][C:12](C1C=CC=CC=1)([C:16]1C=CC=CC=1)[C:13](C)=[CH2:14])=O>C(=S)=S>[CH3:11][C:12]1([CH3:16])[C:6]2[C:1](=[CH:2][CH:3]=[CH:4][CH:5]=2)[O:7][CH2:14][CH2:13]1

Participants

4

Reactant 2

HCID 996PhenolHCID 131715882Diphenyl-3-methyl-3-buten-1-yl phosphate2×

Product 1

HCID 3167634,4-Dimethylchroman

Reagents, catalysts & solvents 1

HCID 6348Carbon DisulfideSolvent

Conditions

Temperature
0 °C

Procedure

To a dry, ice-cooled flask containing 34.95g (0.134 mol) of stannic chloride was added quickly under argon 63.0g (0.669 mol) of phenol. The mixture was stirred at 0 degrees C for 0.5 hour and then treated with 43.0g (0.135 mol) of diphenyl-3-methyl-3-buten-1-yl phosphate (Compound 36), followed by a 5 ml carbon disulfide rinse. The mixture was stirred at room temperature for 21 hours and then quenched by pouring onto 700 g ice and 1 liter of 1.5N NaOH. The mixture was extracted with 1×600 ml and 2×300 ml ether. The combined ether fractions were washed with 2N NaOH, saturated NaCl and dried (MgSO4). Solvent was removed in vacuo and the residue purified by flash chromatography (silica; 2% ether in hexane) to give the title compound as a colorless oil. PMR (CDCl3) &: 1.34 (6H), 1.80-1.85 (2H, m), 4.15-4.20 (2H, m), 6.80 (1H, dd, J~8.1 hz, 1.5 Hz), 6.87 (1H, td, J~8.1 Hz, 1.5 Hz), 7.07 (1H, td, J~8.1 Hz, 1.5 Hz), 7.26 (1H, dd, J~8.1 Hz, 1.5 H).

Workup

  1. temperatureTo a dry, ice-cooled flask
  2. washrinse
  3. stirringThe mixture was stirred at room temperature for 21 hours
  4. customquenched
  5. additionby pouring onto 700 g ice and 1 liter of 1.5N NaOH
  6. extractionThe mixture was extracted with 1×600 ml and 2×300 ml ether
  7. washThe combined ether fractions were washed with 2N NaOH, saturated NaCl
  8. dry with materialdried (MgSO4)
  9. customSolvent was removed in vacuo
  10. customthe residue purified by flash chromatography (silica; 2% ether in hexane)

Sources & evidence

ORD record
ord-ba021c193afc485d91565d45c56c220d
Source dataset
uspto-grants-1991_04
Patent number
US05006550

Linked notes

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