合成路线1

A new synthesis of nileprost has been described: The condensation of the protected lactone (I) with acetonitrile by means of lithium dimethylamide (LDA) gives the cyanomethylene derivative (II), which is condensed with methyl 4-oxobutyrate (III) by means of the same reagent yielding compound (IV). The partial reduction of (IV) with H2 over Pd/C in toluene affords compound (V) with part of the nileprost skeleton. Partial deprotection of (V) with tetrabutylammonium fluoride gives the alcohol (VI), which is oxidized with SO3-pyridine complex to the aldehyde (VII). The Wittig condensation of (VII) with diethyl (2-oxo-3-methylheptyl)phosphonate (VIII) by means of NaH in THF yields the enone (IX), which is deprotected with acetic acid and reduced with diisobutylaluminum hydride in toluene to afford the nileprost methyl ester (X). Finally, this compound is hydrolyzed with NaOH in methanol-water.