The esterification of prostaglandin F2alpha (I) with diazomethane in ethyl ether gives the methyl ester (II), which is treated with butylboronic acid in refluxing toluene yielding the cyclic boronate (III). The silylation of (III) with TBDMS triflate and 2,6-lutidine in dichloromethane, with simultaneous cleavage of the boronate affords the monosylilated prostaglandin (IV), which is treated with triphospgene and pyridine in dichloromethane giving the cyclic carbonate (V). The reduction of (V) with LiBH4 in ethyl ether yields the prostanol intermediate (VI), which is finally desilylalted with TBAF in THF.

The esterification of prostaglandin F2alpha (I) with O-benzyl-N,N'-diisopropylisourea (OBIU) in hot toluene gives the benzyl ester (II), which is treated with butylboronic acid in refluxing toluene yielding the cyclic boronate (III). The silylation of (III) with TBDMS triflate and 2,6-lutidine in dichloromethane, with simultaneous cleavage of the boronate affords the monosylilated prostaglandin (IV), which is treated with triphospgene and pyridine in dichloromethane giving the cyclic carbonate (V). The desilyllation of (V) with tetrabutylammonium fluoride (TBAF) in THF intermediate (VI), which is finally reduced with LiBH4 in ethyl ether.