0.29 ml (1.4 mmol) of a 4.9 M solution of sodium methoxide in methanol were added to a solution of 1.77 g (7.1 mmol) of (2R,3S)-2-(2,3-difluorophenyl)-3-methyl-2-[(1H-1,2,4-triazol-1-yl)methyl]oxirane [prepared as described in Step 7(iv) above] and 2.20 g (9.2 mmol) of trans-5-(acetylthio)-2-phenyl-1,3-dioxane [prepared as described in Japanese Patent Application (Kokai) Hei 8-333350] in 20 ml of ethanol. The resulting mixture was then heated under reflux for 7 hours. After cooling the reaction mixture, it was partitioned between ethyl acetate and an aqueous ammonium chloride solution. The organic layer was washed with saturated aqueous sodium chloride solution and concentrated under reduced pressure to afford 3.65 g of the crude title compound. An aliquot (0.28 g) of the crude residue was purified by chromatography on a silica gel (15 g) column using a 2:5 mixture of ethyl acetate and hexane as eluent to afford 0.21 g of the title compound.
