合成路线1

3) (1R,2R,4R)-4-(2(E)-Bromo-1-propenyl)-2-methoxy-1-(triisopropylsilyloxy)cyclohexane (XLVII).- The catalytic asymetric epoxidation of divinylcarbinol (XXXIII) with titanium isopropoxide and L-(+)-diisopropyl tartrate in dichloromethane gives (2R,3S)-1,2-epoxy-4-penten-3-ol (XXXIV), which is protected with PMB-Br and tetrabutylammonium bromide in dichloromethane yielding the benzyl derivative (XXXV). The condensation of (XXXV) with ethoxyacetylene (V) by means of boron trifluoride ethearate in THF affords the acetylenic ether (XXXVI), which is treated with ethanol and HgCl2 giving ethyl (4R,5S)-5-hydroxy-4-methoxyhept-6-enoate (XXXVII). The lactonization of (XXXVII) by means of p-toluenesulfonic acid in benzene yields the lactone (XXXVIII), which is submitted to a Claisen rearrangement by means of TBS trifluoromethanesulfonate and the resulting acid was methylated with diazomethane to afford methyl (1R,3R)-3-methoxy-4-cyclohexene-1-carboxylate (XXXIX). Hydroboration of (XXXIX) with BH3 and NaOH gives methyl (1R,3R,4R)-4-hydroxy-3-methoxycyclohexane-1-carboxylate (XL), which is protected with TIPS trifluoromethanesulfonate in dichloromethane yielding ester (XLI). The reduction of (XLI) with LiAlH4 in THF affords the hydroxymethyl derivative (XLII), which is oxidized to the corresponding aldehyde (XLIII) by means of oxalyl chloride in dichloromethane - DMSO. The reaction of (XLIII) with dimethyl diazomethylphosphonate and potassium tert-butoxide in THF gives (1R,2R,4R)-4-ethynyl-2-methoxy-1-(triisopropylsilyloxy)cyclohexane (XLIV), which is methylated with methyl iodide and butyllithium in THF to yield the corresponding propynyl derivative (XLV). Finally, this compound is treated with NBS in benzene affording the third building fragment (XLVI) (Scheme 2). 4) The first coupling reaction was the addition of vinyl bromide (XLVI) to aldehyde (XXXII). This was performed by reaction of (XLVI) with butyllithium and the resulting vinyllithium derivative was treated with aldehyde (XXXII) and catalytic amounts of MgBr giving the carbinol (XLVII), which was esterified with N-(tert-butoxycarbonyl)piperidine-2(S)-carboxylic acid (XLVIII) by means of DDC and 4-pyrrolidinopyridine, yielding the corresponding ester (XLIX). Treatment of (XLIX) with Zn dust and NH4Cl affords the 2-allyl substituted alcohol (L), which is oxidized with oxalyl chloride and DMSO in dichloromethane giving a fourth building block, the allyl substituted aldehyde (LI).