This compound can be obtained by three different ways: 1) The methylation of androsta-1,4-diene-3,17-dione (I) with methyllithium and Cu2I2, followed by acetylation with acetic anhydride gives 3-acetoxy-1alpha-methylandrosta-2,4-dien-17-one (II), which is treated with 1,3-dibromo-5,5-dimethylhydantoin (DBDH) in dioxane - water yielding 2alpha(beta)-bromo-1alpha-methylandrost-4-ene-3,17-dione (III). Finally, this compound is dehydrobrominated with MgO in hot DMF. 2) By oxidation of 17beta-hydroxy-1-methylandrosta-1,4-dien-3-one (IV) with chromium trioxide and H2SO4 in acetone. 3) By oxidation of 17beta-hydroxy-1-methylandrost-1-en-3-one (V) with iodoxybenzene and diphenyldiselenide in hot toluene.
FK-352 can be obtained by two related ways: 1) The Wittig condensation of 2-phenylpyrazolo[1,5-a]pyridine-3-carbaldehyde (I) with trimethyl phosphonoacetate (II) by means of NaH in hot toluene gives 3-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)-2(E)-propenoic acid methyl ester (III), which by hydrolysis with aqueous NaOH yields the expected free acid (IV) (1). The reaction of (IV) with SOCl2 and DMF in dichloromethane affords the corresponding acyl chloride (V), which is condensed with 2-[2(R)-piperidinyl]acetic acid ethyl ester (VI) by means of triethylamine in dichloromethane affording the acylated piperidine (VII). Finally, this compound is hydrolyzed with NaOH in refluxing methanol. 2) The free acid precursor (IV) can also be obtained by condensation of 2-phenylpyrazolo[1,5-a]pyridine (VIII) with 3-(dimethylamino)acrylic acid ethyl ester (IX) by means of AlCl3 in methylene chloride giving the ethyl ester (X), which is hydrolyzed to the free acid (IV) by treatment with aqueous NaOH.