反应详情

A 30% solution of hydrogen bromide in acetic acid (12 mL) was added to the product of 1a (3.3 g; 9.5 mmol) cooled with an ice-water bath and stirred until the oil dissolved with evolution of gas. After stirring for 15 min, the mixture was triturated with hexane (4×20 mL) and diethyl ether (4×20 mL); the oil solidified to a tan powder. The residue was filtered and dried overnight in a drying pistol at ˜50° C. and 12 mm Hg. 4.44 g (92%) product was obtained (tan powder, mp 110-114° C. (dec.)).

1. temperaturecooled with an ice-water bath
2. dissolutiondissolved with evolution of gas
3. stirringAfter stirring for 15 min
4. customthe mixture was triturated with hexane (4×20 mL) and diethyl ether (4×20 mL)
5. filtrationThe residue was filtered
6. customdried overnight in a drying pistol at ˜50° C.