반응 #952822

반응 방정식

pinanediol (R)-1-chloro-5-bromopentylboronate

ammonium chloride

methylmagnesium bromide

→

pinanediol (R)-5-bromo-1-methylpentylboronate

용매

THF

—

Petroleum ether

반응 조건

후처리

1. 1
   workup.ADDITIONwere mixed
2. 2
   온도The solution was warmed to room temperature overnight
3. 3
   기타forming an emulsion
4. 4
   기타The aqueous phases were separated
5. 5
   세척The organic phase was washed with saturated ammonium chloride (2×250 ml)
6. 6
   세척The combined aqueous phases were washed with petroleum ether (2×250 ml)
7. 7
   건조The combined organic phases were dried over sodium sulfate
8. 8
   여과filtered
9. 9
   기타evaporated under vacuum

실험 절차

In a 500 ml round bottomed flask, 300 ml of anhydrous THF and the crude pinanediol (R)-1-chloro-5-bromopentylboronate from the previous reaction (assuming 89 g; 0.247 moles) were mixed and cooled to -78° C. with stirring under argon. To the solution was added methylmagnesium bromide (3.26N, 79.6 ml). The solution was warmed to room temperature overnight. Petroleum ether (500 ml) and saturated ammonium chloride (250 ml) were added, forming an emulsion. The aqueous phases were separated. The organic phase was washed with saturated ammonium chloride (2×250 ml), causing the emulsion to disappear. The combined aqueous phases were washed with petroleum ether (2×250 ml). The combined organic phases were dried over sodium sulfate, filtered and evaporated under vacuum to yield 85.85 g of crude pinanediol (R)-5-bromo-1-methylpentylboronate.

출처