4,5-Dihydro-2-(methylthio)thiazole → (4R)-4,5-Dihydro-2-(methylthio)-4-thiazolemethanol

To a 73 ml solution of methanol anhydride containing 7.95 g of 3-hydroxyazetidine hydrochloride (5) obtained in the above Example 3, there was added 5.09 g of potassium hydrogencarbonate at a room temperature, and, then, there was added 9.67 g of 2-(methylthio)-1,3-thiazoline dropwise, and, then, the resultant solution was subjected to heating and reflux for 20 hours. After the reaction liquid was left still until it had a room temperature, 3.63 g of potassium hydrogencarbonate was further added, and the liquid was stirred for one hour at the same temperature. After the reaction was over, precipitate was removed by filtration, and the solvent was evaporated in a vacuum, and, to the obtained residue, there was added 100 ml of tetrahydrofuran, and the resulting mixture was stirred for one hour at a room temperature. Insoluble matters were removed by filtration, and the solvent was evaporated in a vacuum, and, then, the residue was subjected to silica gel column chromatography (eluent: chloroform-methanol), and, thus, there was obtained 8.23 g (yield: 71.5%) of 3-hydroxy-1-(1,3-thiazolin-2-yl)azetidine (6) in the form of colorless crystal.