Water → (R)-(+)-3-Chlorostyrene oxide

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A 2-necked round-bottom flask equipped with a water-cooled overhead stirrer was charged with 3-chlorostyrene (5.01 g, 3.61×10−2 mol), CH2Cl2 (45 mL), (R,R)-3 (0.578 g, 9.10×10−4 mol), and 4-PPNO (0.924 g, 5.40×10−3 mol). The solution was cooled to 0° C., and precooled buffered bleach (0.6 M, 75 mL, 4.50×10−2 mol, Clorox®, buffered to pH=11.3 with 0.05 M Na2HPO4 and 1M NaOH) was added. The two phase system was stirred vigorously, and the course of the reaction was monitored by GC. Upon complete consumption of starting olefin (<6 h), the reaction mixture was filtered through a plug of Celite on a coarse glass frit and washed with CH2Cl2 (75 mL). The organic layer of the filtrate was washed with distilled water (2×25 mL), and the aqueous layers were extracted with CH2Cl2 (2×25 mL). The combined organic layers were dried over Na2SO4 and concentrated in vacuo. Removal of the catalyst was effected by elution through a pad of SiO2 (30 g) using pentane and CH2Cl2 (1:1). The eluent was concentrated in vacuo, and subsequent bulb-to-bulb distillation (70° C., 0.6 mm Hg) from CaH2 afforded (R)-3-chlorostyrene oxide (5.15 g, 92%) as a pale yellow liquid in 32% ee.

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