合成路线1

The decarboxylative hydrolysis ot 2beta,4alpha-di(methoxycarbonyl)-3alpha-(3-phenylpropyl)cyclopentanone (I) with HCl in refluxing acetic acid gives 3alpha-(3-phenylpropyl)cyclopentanone-4alpha-carboxylic acid methyl ester (II), which by successive reactions with oxalyl chloride in refluxing benzene, with diazomethane in ether, and with silver benzoate and triethylamine in methanol, is converted to 3alpha-(3-phenylpropyl)cyclopentanone-4alpha-acetic acid methyl ester (III). The dehydrogenation of (III) by reaction with N-bromosuccinimide and sodium selenobenzene in benzene and THF affords 3alpha-(3-phenyl-2-propenyl)cyclopentanone-4alpha-acetic acid methyl ester (IV), which is oxidized with sodium methaperiodate and Jones reagent, and methylated with diazomethane to give cyclopentanone 3alpha,4alpha-di(acetic acid) dimethyl ester (V). The reaction of (V) with ethyl eneglycol and p-toluenesulfonic acid yields the corresponding ketal (VI), which is submitted to a cyclization with sodium methoxide in hot methanol - DMSO to afford 7,7-ethylenedioxybicyclo[3.3.0] octan-3-one-4beta-carboxylic acid methyl ester (VII). The reduction of (VII) with NaBH4 in methanol gives the corresponding hydroxyester (VIII), which is protected with dihydropyran and p-toluenesulfonic acid to the corresponding tetrahydropyranyloxy compound (IX). The reduction of (IX) with LiAlH4 in ether affords the methanol derivative (X), which is oxidized with CrO3 - pyridine to the aldehyde (XI). The Wittig condensation of (XI) with dimethyl 2-oxo-4R,8-dimethyl-7-nonenylphosphonate (XII) by means of NaH in THF affords the dienic ketone (XIII).