Water → rac-(1R,2R)-2-(4-fluorophenyl)cyclopropane-1-carboxylic acid

A suspension of the product from step b) (3.74 g) and lithium hydroxide monohydrate (4.11 g) in tetrahydrofuran (100 ml)/ water (3 ml) was stirred at 50° C. for 24 hours. The reaction mixture was concentrated in vacuo, and the residue dissolved in water (100 ml), acidified with 2N HCl and extracted into dichloromethane (3×75 ml). The organics were dried and concentrated. Purification (SiO2, isohexane:diethylether 2:1 as eluant) gave the subtitle compound as a colourless solid (1.78 g).