Boron tribromide → 4-[3,5-Dimethyl-4-hydroxyphenyl]butanol

Participants

Reaction Steps

A solution of 4-[3,5-dimethyl-4-methoxyphenyl]butanol (PREPARATION NA-14, 4.96 g), boron tribromide (1.0M in methylene chloride, 47 ml) in methylene chloride (200 ml) is stirred at -70° and then allowed to warm to 20°-25° over 4 hr. The reaction did not begin until the reaction reached room temperature. The reaction mixture is partitioned between methylene chloride and aqueous sodium bicarbonate. The organic phase is dried over sodium sulfate and concentrated to give the phenol which had a consistent NMR. A sample of the phenol (5.00 g) is dissolved in methylene chloride (100 ml) and is treated at 0° with triethylamine (6.28 g) and methanesulfonyl chloride (7.09 g). After 3 hr, the reaction mixture is partitioned between methylene chloride and aqueous sodium bicarbonate. The organic phase is dried over sodium sulfate and concentrated to give the title compound which had an NMR consistent for the bis-mesylate.

Provenance & Evidence