合成路线1

The hydrolysis of 2-oxa-3-oxo-6-syn-hydroxymethyl-7-anti-acetoxy-cis-bicyclo[3.3.0]octane (VIII) (2) with KOH in methanol gives the dihydroxy compound (IX), which is acetylated with acetic anhydride in pyridine to give the acetoxymethyl compound (X). The treatment of (X) with dihydropyran and p-toluenesulfonic acid in methylene chloride affords the tetrahydropyranyl derivative (XI), which is reduced with diisobutylaluminum hydride in toluene to yield 2-oxa-3-hydroxy-6-syn-hydroxymethyl-7-anti-(2-tetrahydropyranyloxy)-cis-bicyclo[3.3.0]octane (XII). The Wittig reaction of (XII) with 4-carboxybutyltriphenylphosphonium bromide (B) by means of NaH in DMSO gives 2alpha-(6-carboxyhex-2-cis-enyl)-3beta-hydroxymethyl-4alpha-(2-tetrahydropyranyloxy)cyclopentan-1alpha-ol (XIII), which is esterified with CH2N2 to the corresponding methyl ester (XIV). The reaction of (XIV) with trimethylchlorosilane in pyridine - methylene chloride gives the monotrimethylsilyl derivative (XV), which is acetylated with acetyl chloride affording the fully protected compound (XVI). The partial hydrolysis of (XVI) with oxalic acid in water-ethyl acetate yields the compound (XVII) with a free hydroxymethyl group, which is finally oxidized with CrO3 in methylene chloride pyridine to give the starting 1alpha-acetoxy-2alpha-(6-methoxycarbonylhex-2-cis-enyl)-3beta-formyl-4alpha-(2-tetrahydropyranyloxy)cyclopentane (I).