合成路线1

A new synthesis of racemic rosaprostol has been reported: The condensation of methyl decanoate (I) with dimethyl methylphosphonate (II) by means of butyllithium in THF gives dimethyl 2-oxoundecylphosphonate (III), which is treated with tosyl azide and NaH in benzene/THF yielding the alpha-diazo compound (IV). The cyclization of (IV) by means of rhodium acetate in refluxing dichloromethane affords trans-2-(dimethoxyphosphoryl)-3-hexylcyclopentanone (V), which is condensed with methyl 6-formylhexanoate (VI) by means of NaOH/Al2O3 in benzene giving methyl 6-(2-hexyl-5-oxocyclopentylidene)hexanoate (VII). The selective reduction of (VII) with sodium tellurohydride (NaHTe) in ethanol gives the saturated ester (VIII), which is hydrolyzed with NaOH in hot ethanol yielding the corresponding free acid (IX). Finally, this compound is reduced to the target compound with NaBH4 in methanol.