Methyl 3-(1-(4-fluorophenyl)-1H-indazol-5-yl)-3-hydroxy-2,2,5-trimethylhexanoate (280 mg, 0.7 mmol) was dissolved in 10 mL MeOH and 5 mL H2SO4 and heated at 90° C. for 12 h. After 12 h, diluted with water and extracted with EtOAc×3. The organic layers were dried over MgSO4, filtered, and concentrated. The residue was purified by SiO2 chromatography eluting with 1:9 EtOAc/hexane. Obtained 220 mg (82% yield) of (E)-methyl 3-(1-(4-fluorophenyl)-1H-indazol-5-yl)-2,2,5-trimethylhex-3-enoate. MS found: (M+H)+=381.
