Monoketal (I) is acylated with dimethylcarbonate to (II), reduced with NaBH4 to give (III) and protected with tert-butyldimethylsilylchloride to give (IV). After selective reduction of the ester function of (IV) with DIBAH, the resulting aldehyde (V) undergoes a Wittig-Horner-reaction with dimethyl 2-oxo-2-cyclohexylethylphosphonate to give (VI), which is subsequently reduced with NaBH4. After separation of the epimeric alcohols by silica flash chromatography, (VII) is deprotected with a AcOH/THF/water mixture. Wittig reaction of 3-methoxycarbonylphenylmethylene-triphenylphosphorane with (VIII) gives a mixture of E/Z-isomers, which is separated by preparative HPLC. Ester hydrolysis with KOH and acidification of the E-isomer gives naxaprostene (IX), R = H.