Sodium Hydroxide → HCID 69311668, compound

4-[1,3]Dioxan-2-yl-butyric acid methyl ester (6.8 g, 0.036 mol) was added to a stirred solution of sodium hydroxide (1.87 g, 0.047 mol) in water (30 ml) and methanol (30 ml). The mixture was stirred for 18 h at room temperature and then the solvent evaporated. The residue was partitioned between ethyl acetate (100 ml) and water (100 ml) and cooled to 0° C. The mixture was acidified with hydrochloric acid (1M) to pH 2 and the layers separated. The aqueous layer was further extracted with cold ethyl acetate (100 ml) and the combined organic layers washed with brine (100 ml) and then dried (Na2SO4). The solvents were evaporated and the crude solid (5.56 g) was used in the next step.