Pyridine → (+/-)-(6-Acetoxy-2,5,7,8-tetramethylchroman-2-yl)acetic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of 66.1 g. (0.25 mol.) of (±)-(6-hydroxy-2,5,7,8-tetramethylchroman-2-yl)acetic acid and 250 ml. each of pyridine and acetic anhydride was stirred at 25°C. under N2 for 20 hours and stripped of solvent at 40°C. to give an orangebrown oil. To a suspension of this material in 500 ml. of H2O and 100 ml. of tetrahydrofuran was added 166 g. (2.0 mol.) of NaHCO3. The suspension was stirred at 25°C. for 4.0 hours, washed with ether, acidified with 2N-aqueous HCl and extracted with ether. The ether solutions were washed with saturated brine, dried over sodium sulfate and stripped of solvent to give (±)-(6-acetoxy-2,5,7,8-tetramethylchroman-2-yl)acetic acid as an orangeish resin. Crystallization from diethyl ether petroleum ether (b.p. 30°-60°C.) gave (±)-(6-acetoxy-2,5,7,8-tetramethylchroman-2-yl)acetic acid as a granular white solid.

Provenance & Evidence