反应详情

温度

20 °C

21.7 mmol of n-butyllithium (1.59 molar in n-hexane, 13.6 ml) were added at -78 C to a solution of (4R,5R)-4,5-bis(hydroxymethyl)-2,2-dimethyl-1,3-dioxolane (3.32 g, 20.5 mmol) in 60 ml of tetrahydrofuran ((4R,5R)-4,5-bis(hydroxymethyl)-2,2-dimethyl-1,3-dioxolane was prepared according to J. Org. Chem. 33 (1968), page 2171). After stirring for 10 minutes, a solution of p-toluenesulfonyl chloride (4 g, 21 mmol) in 20 ml of tetrahydrofuran which was cooled to −78° C. was added. After stirring at −78° C. for 15 minutes, the mixture was warmed to 20° C. and poured into 200 ml of concentrated sodium chloride solution. The organic phase was separated off and the aqueous phase was extracted twice with 50 ml of ethyl acetate. The combined organic phases were dried over anhydrous sodium sulfate and then concentrated. The residue was chromatographed on 400 g of silica gel using ethyl acetate and n-hexane in the weight ratio 60:40 as eluent. 74.6% of (4R,5R)-[5-hydroxymethyl-2,2-dimethyl-1,3-dioxolan-4-yl]methyl p-toluenesulfonate were obtained ([α]D19=+11.80 (c=1.88 in trichloromethane); cf. J. Org. Chem. 55 (1990), page 4417: [α]D21=+11.30 (c=2.70 in trichloromethane)).

1. additionwas added
2. stirringAfter stirring at −78° C. for 15 minutes
3. customThe organic phase was separated off
4. extractionthe aqueous phase was extracted twice with 50 ml of ethyl acetate
5. dry with materialThe combined organic phases were dried over anhydrous sodium sulfate
6. concentrationconcentrated
7. customThe residue was chromatographed on 400 g of silica gel