反应详情

A solution of 2-(1-hydroxy-ethyl)-[1,4]dioxane-2-carboxylic acid methyl ester (1.49 g, 7.8 mmol) in pyridine (8 mL) was stirred at room temperature. 4-Toluenesulfonyl chloride (1.50 g, 7.8 mmol) was added and the reaction mixture was stirred at room temperature for 18 h. The majority of the pyridine was evaporated, 1 M hydrochloric acid was added to acidify the mixture to pH 2 and the mixture was extracted with ethyl acetate. The organic extracts were combined and washed with brine. The organic solution was filtered through a hydrophobic frit and the filtrate was evaporated. The residue was purified by silica gel chromatography using a gradient of pentane/diethyl ether 3:1 to 0:1 to afford the title compound (1.70 g, 63%) as a yellow gum and as a 3:1 mixture of diastereoisomers. LCMS (m/z) 367.0 [M+Na], Tr=2.44 min.

1. customThe majority of the pyridine was evaporated
2. addition1 M hydrochloric acid was added
3. extractionthe mixture was extracted with ethyl acetate
4. washwashed with brine
5. filtrationThe organic solution was filtered through a hydrophobic frit
6. customthe filtrate was evaporated
7. customThe residue was purified by silica gel chromatography