Sulfuric Acid → 2,2,4,4-Tetramethylchroman

Participants

Reaction Steps

A mixture of 2.98 g (14.3 mmol) of 2-(1,1,3-trimethyl-3-hydroxybutyl) phenol (Compound 39) and 40 ml of 20% aqueous H2SO4 was heated at reflux, under nitrogen, for 4 h. The mixture was stirred at room temperature for a further 72 h and then diluted with 50 ml of water. The mixture was extracted with 3×20 ml of hexanes. The organic extracts were then combined and washed successively with water and saturated NaCl solution and then dried (MgSO4). The solvent was then removed in vacuo to give the title compound as a colorless oil. PMR (CDCl3): & 1.36 (dH, s), 1.37 (dH, s), 1.83 (2H, s), 6.71 (1H, dd, J-8.2 Hz, 1.5 Hz) 6.92 (1H, td, J-8.2 Hz, 1.5 Hz), 7.09 (1H, td, J-8.2 Hz, 1.5 Hz), 7.29 (1H, dd, J-8.2 Hz, 1.5 Hz).

Provenance & Evidence