Reaction #1583864

Reaction equation

7-(tert-Butyldimethylsilyloxy)-3-(4-(tert-butyldimethylsilyloxy)phenyl)-4-(4-methoxyphenyl)chroman-4-ol

pTsOH

ethanol

→

3-(4-Hydroxyphenyl)-4-(4-methoxyphenyl)-2H-chromen-7-ol

Solvents

methanol

Conditions

Workup

1. 1
   Otherwere combined in a 2-neck 5 L round bottom flask with condenser
2. 2
   TemperatureThe reaction was heated
3. 3
   Temperatureat reflux for 3 hours
4. 4
   ConcentrationThe solvent was concentrated in vacuo to ˜100 ml
5. 5
   workup.ADDITIONbefore being poured
6. 6
   Temperatureinto chilled
7. 7
   ExtractionThe mixture was then extracted with ethyl acetate
8. 8
   Washthe combined organic layers washed with water (3×2 L), brine (1×500 ml)
9. 9
   Dryingdried over anhydrous magnesium sulphate
10. 10
    Filtrationfiltered
11. 11
    Othersolvent removed in vacuo
12. 12
    Otherto give red/brown oil

Procedure

7-(tert-Butyldimethylsilyloxy)-3-(4-(tert-butyldimethylsilyloxy)phenyl)-4-(4-methoxyphenyl)chroman-4-ol (42 g), pTsOH (435 g), boiling chips and 2.5 L of ethanol were combined in a 2-neck 5 L round bottom flask with condenser attached. The reaction was heated at reflux for 3 hours. The solvent was concentrated in vacuo to ˜100 ml before being poured into chilled, stirred water (700 ml). The mixture was then extracted with ethyl acetate, the combined organic layers washed with water (3×2 L), brine (1×500 ml), dried over anhydrous magnesium sulphate and filtered and solvent removed in vacuo to give red/brown oil. The oil was dissolved in methanol (˜100 ml) and put in freezer overnight.

Source