合成路线1

The controlled epoxidation of 1,3-cyclooctadiene (XXI) gives the monoepoxide (XXII), which by isomerization is converted into the bicyclic alcohol (XXIII). The epoxidation of (XXIII) with tert-butyl hydroperoxide (E) and vanadyl acetylacetonate in refluxing benzene gives the epoxide (XXIV), which is protected with tert-butyldimethylsilyl chloride yielding the corresponding silylether (XXV). The reaction of (XXV) with 1,3-bis(methylthio)allyllithium (XXVI) in THF gives the condensation product (XXVII), which by treatment with HgCl2 and CaCO3 affords the hydroxyaldehyde (XXVIII). The reaction of (XXVIII) with n-amyllithium (F) in THF yields the diol (XXIX), which is protected with dihydropyran giving the bistetrahydropyranyl derivative (XXX). Elimination of the silyl group of (XXX) with tetrabutylammonium fluoride gives rise to the monohydroxybis(tetrahydropyranyl) derivative (XXXI), which is mesylated with methanesulfonyl chloride to the corresponding mesylate (XXXII). The treatment of (XXXII) with KOH in refluxing ethanol yields the diene (XXXIII), which is selectively epoxidized with m-chloroperbenzoic acid to the epoxide (XXXIV).