Hydrochloric Acid → HCID 21546969, compound

A solution of 150 mg. of 1-hydroxy-3-cyclopentene-1-carbonitrile in 10 ml. of anhydrous methanol and 5 ml. of anhydrous diethyl ether is cooled in an ice-bath. The solution is saturated with gaseous hydrogen chloride, then allowed to warm to room temperature and finally set aside overnight. The solution is then concentrated in vacuo to a solid, which is dissolved in approximately 10 ml. of water. After 23/4 hours an aliquot is removed and extracted with methylene chloride. The extract is dried using sodium sulfate, and it is concentrated in vacuo giving methyl 1-hydroxy-3-cyclopentene-1-carboxylate as a yellowish oil. The infrared spectrum of the product (in CDCl3) shows an absorption at 1730 cm-1, confirming the presence of an ester function. The nmr spectrum of the product (in CDCl3) shows absorptions at 5.7 ppm (singlet, olefinic hydrogens), 3.8 ppm (singlet, methyl hydrogens) and 3.3-2.2 ppm (singlet superimposed on a quartet, hydroxy group and methylene hydrogens). The remainder of the aqueous solution is worked up analogously to give a further quantity of product. The combined yield is 65.8 mg.