Sodium Hydroxide → 7-[4,5-Bis-(4-fluoro-phenyl)-2-isopropyl-imidazol-1-yl]-3,5-dihydroxy-hept-6-enoic acid

A solution of 1,1-dimethyleth-1-yl (3R,5S,E)-7-[4,5-bis(4-fluorophenyl)-2-(1-methylethyl)-1H-imidazol-1-yl]-3,5-dihydroxy-6-heptenoate (726 mg) in redistilled THF (40 ml) was treated with 0.1M aqueous sodium hydroxide solution (14.5 ml). After 1/2 h the mixture was concentrated to ca. 10 ml and then diluted with water (50 ml). The mixture was acidified to pH2 with 2N-hydrochloric acid, brought back to pH4 with aqueous sodium hydrogen carbonate solution, ammonium sulphate added and then the mixture was extracted with ethyl acetate (3×50 ml). The combined extracts were dried and concentrated to ca. 4 ml when a solid crystallised. The crystals were collected and dried to give the title compound (500 mg), m.p. 172°-3° C., [α]D +15.7° (c 1.02, DMSO), (RS:SR=99.5:0.5).