Phenol → 4,4-Dimethylchroman

Participants

Reaction Conditions

Reaction Steps

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 75), 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) δ: 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).

Provenance & Evidence