合成路线1

The two major metabolites of raloxifene, the glucuronide conjugates (VI) and (VIII) are synthesized as follows: The partial silylation of raloxifene (I) with tert-butyldimethylsilyl chloride (TBDMS-Cl) by means of dimethylaminopyridine (DMAP) in THF/DMF gives a mixture of the monosilylated compounds (II) and (III), which are separated by chromatography. Compounds (II) and (III) are independently condensed with methyl 1,2,3,4-tetra-O-acetyl-D-glucuronate (IV) by means of BF3.OEt2 in dichloromethane yielding protected glucuronides (V) and (VII), respectively. Finally, both compounds are deprotected by a treatment first with LiOH in dioxane to hydrolyzed the ester groups, and then with tetrabutylammonium fluoride in THF to eliminate the silyl groups, thus obtaining the desired metabolites (VI) and (VIII), respectively.