Sulfuric Acid → HCID 22618794, compound

Participants

Reaction Steps

To a solution of 8-hydroxy-8-(2-phenylethyl)-1,4-dioxaspiro[4.5]decane (12.8 g) in acetonitrile (200 ml), a concentrated sulfuric acid (5.7 ml) was dropwise added under ice-cooling over 3 minutes. The reaction mixture was left standing at room temperature for 2 days, poured into a saturated aqueous sodium hydrogencarbonate solution under ice-cooling and extracted with ethyl acetate. The ethyl acetate layer was washed with water and a saturated brine and dried over anhydrous magnesium sulfate. The solvent was distilled away under reduced pressure to give 8-acetamido-8-(2-phenylethyl)-1,4-dioxaspiro[4.5]decane as a crude product. The crude product was dissolved in tetrahydrofuran (140 ml) without purifying and thereto was added a 0.1N aqueous hydrochloric acid solution (30 ml) at room temperature and the mixture was allowed to stand overnight. The mixture was carefully poured into a ice-cooled saturated aqueous sodium hydrogencarbonate solution and extracted with ethyl acetate. The ethyl acetate layer was washed with water and a saturated brine, dried over anhydrous magnesium sulfate and the solvent was distilled away to give crude crystals. The crystals were recrystallized from a mixed solvent (1:1) of 1,2-dimethoxyethane-diisopropyl ether to give 1/5 hydrate of the subject compound (5.1 g) as white crystals, melting at 140-143° C.

Provenance & Evidence