2-Propanone, 1-(1-oxopropoxy)- → HCID 24885943, Verbindung
Reaktionsgleichung
[CH3:1][C:2]1([CH2:20][O:21][C:22](=[O:25])[CH2:23][CH3:24])[O:7][CH2:6][C:5]([CH2:14]OC(=O)CC)([CH2:8][O:9]C(=O)CC)[CH2:4][O:3]1.[C:26]([O:30][CH2:31][C:32](=[O:34])[CH3:33])(=[O:29])[CH2:27][CH3:28]>>[CH3:1][C:2]1([CH2:20][O:21][C:22](=[O:25])[CH2:23][CH3:24])[O:7][CH2:6][C:5]2([CH2:8][O:9][C:32]([CH3:33])([CH2:31][O:30][C:26](=[O:29])[CH2:27][CH3:28])[O:34][CH2:14]2)[CH2:4][O:3]1Komponenten
3
Versuchsvorschrift
A solution of propionyloxyacetone (10 g, 76.8 mmol), pentaerythritol (5.22 g, 38.4 mmol), and pyridinium p-toluenesulfonate (1.0 g, 4 mmol) in toluene (200 ml) was stirred under reflux for 6 hours, while water was removed using a Dean-Stark water separator. After cooling to room temperature, the reaction liquid was poured into ethyl acetate (300 ml)/an aqueous sodium hydrogencarbonate solution (350 ml). After phase separation, the organic layer was washed twice with water (200 ml), and once with saturated brine (200 ml), and then dried over sodium sulfate. After the sodium sulfate was filtered out, the solvent was distilled off under reduced pressure, to obtain 11.0 g of a concentrate residue. As a result of measurement of NMR spectra of the concentrate residue, it was found that the by-product of Comparative Example 1 (2-methyl-2,5,5-tris(propionyloxymethyl)-[1,3]dioxane) was hardly detected, while other by-products were formed, and that the starting material propionyloxyacetone remained at a similar level to that in Comparative Example 1. The concentrate residue was purified by column chromatography (eluent: ethyl acetate/hexane=1/2), to give 3,9-dimethyl-3,9-bis(propionyloxymethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane (7.3 g, 20.3 mmol, yield 53%).