Sulfuric Acid → 2,2,4,4,7-Pentamethyl-chroman
Reaction equation
[CH3:1][C:2]([C:9]1[CH:14]=[CH:13][C:12]([CH3:15])=[CH:11][C:10]=1[OH:16])([CH3:8])[CH2:3][C:4]([CH3:7])(O)[CH3:5].S(=O)(=O)(O)O>>[CH3:7][C:4]1([CH3:5])[CH2:3][C:2]([CH3:1])([CH3:8])[C:9]2[C:10](=[CH:11][C:12]([CH3:15])=[CH:13][CH:14]=2)[O:16]1Participants
3
Procedure
To 2.16 g (11.7 mmol) of 2-(1,1,3-trimethyl-3-hydroxybutyl) 5-methyl-phenol (Compound 45) was added under nitrogen 50 ml of 20% aqueous sulfuric acid. The reaction mixture was heated at reflux for 13 h and then cooled. The organic layer was separated and the aqueous layer was extracted with ether. The organic extracts were combined and washed successively with water, saturated NaHCO3 solution, water again and saturated NaCl solution and then dried (MgSO4). The solvent was removed in vacuo to give the title compound as a yellow oil. PMR (CDCl3): & 1.32 (6H, s), 1.34 (6H, s), 1.81 (2H s) 2.26 (3H s) 6.63 (1H, s), 6.72 (1H, d, J~7.9 Hz), 7.15 (1H, d, J~7.9 Hz).
Workup
- temperatureThe reaction mixture was heated