The reaction of methyl 9alpha,11alpha,15(S)-trihydroxy-17(S),20-dimethylprosta-5(Z),13(E)-dienoate (I) with I2 and NaHCO3 in water dichloromethane gives the iodoepoxy compound (II), which is treated with dihydropyran-p-toluenesulfonic acid in dichloromethane to protect the hydroxyl groups yielding the bistetrahydropyranyl derivative (II). The dehydrohalogenation of (III) with 1,5-diazabicyclo[5.4.O]-5-undecene (DBU) followed by hydrolysis with HCl affords the hydroxyketone (IV), which is further oxidized with CrO3-MnSO4-H2SO4 to the diketone (V). Finally, this compound is deprotected with aqueous acetic acid in THF.

The reaction of methyl 9alpha,11alpha,15(S)-trihydroxy-17(S),20-dimethylprosta-5(Z),13(E)-dienoate (I) with I2 and NaHCO3 in water dichloromethane gives the iodoepoxy compound (II), which is treated with dihydropyran-p-toluenesulfonic acid in dichloromethane to protect the hydroxyl groups yielding the bistetrahydropyranyl derivative (II). The dehydrohalogenation of (III) with 1,5-diazabicyclo[5.4.O]-5-undecene (DBU) followed by hydrolysis with HCl affords the hydroxyketone (IV), which is further oxidized with CrO3-MnSO4-H2SO4 to the diketone (V). Finally, this compound is deprotected with aqueous acetic acid in THF.

The reaction of methyl 9alpha,11alpha,15(S)-trihydroxy-17(S),20-dimethylprosta-5(Z),13(E)-dienoate (I) with I2 and NaHCO3 in water dichloromethane gives the iodoepoxy compound (II), which is treated with dihydropyran-p-toluenesulfonic acid in dichloromethane to protect the hydroxyl groups yielding the bistetrahydropyranyl derivative (II). The dehydrohalogenation of (III) with 1,5-diazabicyclo[5.4.O]-5-undecene (DBU) followed by hydrolysis with HCl affords the hydroxyketone (IV), which is further oxidized with CrO3-MnSO4-H2SO4 to the diketone (V). Finally, this compound is deprotected with aqueous acetic acid in THF.