反应详情

n-Butyllithium (1.5M in hexane, 12 ml) was added over 5 min to a stirred solution of 2-methyl-1,3-dithiane (2.4 g) in dry THF (30 ml) at 70° under nitrogen. The yellow solution was then stirred at -30° to -20° for 2 h, cooled to -78° and treated with a solution of the product of stage (iii) (6.1 g) in THF (25 ml). The solution was stirred at room temperature overnight, the solvent was evaporated and the residue was purified by FCC (hexane→System D 9:1) to give the title compound as a pale yellow oil (3.2 g) T.l.c. (System D 9:1) Rf 0.18.

1. temperaturecooled to -78°
2. stirringThe solution was stirred at room temperature overnight
3. customthe solvent was evaporated
4. customthe residue was purified by FCC (hexane→System D 9:1)