合成路线1

The known chiral epoxide (IX) can be synthesized by several different ways shown in the following: 1) 2(S)-Acetoxypropionic acid (XII) is treated first with oxalyl chloride in DMF/CH2Cl2, and then the resultant acyl chloride is submitted to a Friedel-Crafts reaction with 1,3-difluorobenzene (XIII) by means of AlCl3 to provide a 1:1 mixture of a(S)-acetoxypropiophenone (XIV) and a(S)-hydroxy-propiophenone (XV). This mixture is treated with H2SO4 in MeOH to give the pure alcohol (XV). Tosylation of alcohol (XV) with p-toluenesulfonyl chloride in pyridine furnishes tosylate (XVI), which is converted into a(R)-hydroxypropiophenone (XVII) by an SN2 displacement reaction with LiOH in DMF/H2O. Reaction of the hydroxy group of (XVII) with 2,3-dihydropyran (XVIII) and pyridi-nium p-toluenesulfonate (PPTS) in CH2Cl2 gives the protected compound (XIX), which is converted into the silyl alcohol (XXI) by a Grignard reaction with (chloro-methyl)dimethylisopropoxysilane (XX) in the presence of Mg and a small amount of MeI. Oxidative desilylation of (XXI) by means of NaHCO3 and H2O2 in THF/MeOH, followed by hydrolysis with TsOH in MeOH, affords the triol (XXII), which is then mesylated with methanesulfonyl chloride in pyridine to provide the dimesylate (XXIII). Finally, nucleofilic substitution of one mesylate group of (XXIII) with 1H-1,2,4-triazole (XXIV) by means of NaH in DMF with concomitant epoxide formation affords the desired intermediate (IX).