合成路线1

The condensation of sultam (XXII) with propenoyl chloride (XXIII) by means of TEA in dichloromethane gives the acryloyl sultam (XXIV), which is submitted to a Diels Alder cyclization with butadiene (XXV) by means of EtAlCl2 in dichloromethane to yield the chiral cyclohexenylcarbonyl derivative (XXVI). The hydrolysis of (XXVI) with LiOH in THF affords 3-cyclohexene-1(R)-carboxylic acid (XXVII), which is treated with I2, KI, NaHCO3 and DBU to provide the bicyclic lactone (XXVIII). The reduction of (XXVIII) with LiAlH4 in THF gives the chiral diol (XXIX), which is treated with diphenyl disulfide and tributylphosphine to yield the phenyl thioether (XXX). The methylation of the OH group of (XXX) with methyl iodide and KOH in DMSO afford the methoxy derivative (XXXI). The oxidation of (XXXI) with oxone in THF/methanol provides the sulfone (XXXII), which is submitted to hydroboration with BH3/Me2S and tBu-OOH in THF to give the chiral 4-hydroxy-3-methoxycyclohexylmethyl sulfone (XXXIII). The reaction of (XXXIII) with Tbdps-Cl and imidazole in DMF yields the silyl ether (XXXIV), which is condensed with the intermediate butyraldehyde (X) by means of BuLi in THF to afford the chiral pentanol derivative (XXXV). The oxidation of (XXXV) with TFAA and DMSO in dichloromethane provides the corresponding ketone (XXXVI), which is desulfonated by means of aluminum amalgam in refluxing THF/water to give the ketone (XXXVII). The reaction of (XXXVII) with Tf2N-Ph and KHMDS in THF yields the triflate enol ester (XXXVIII), which is methylated with Me-Li and CuI in THF to afford the unsaturated dithiane derivative (XXXIX). The reaction of (XXXIX) with NaH and Tips-OTf in HMPA provides the triisopropylsilyl ether (XL) (1) (Scheme 12407109c). The condensation of (XL) with the intermediate 14-iodo-10-tetradecenal dimethylacetal (XXI) by means of BuLi in THF/HMPA gives the adduct (XLI), which is desulfurized by means of NCS and AgNO3 in acetone/THF/water to yield the ketonic product (XLII). The cleavage of the 4-methoxybenzyl group of (XLII) by means of DDQ in dichloromethane affords the beta-hydroxyketone (XLIII). The reduction of the ketonic group of (XLIII) with LiAlH4 and LiI in ethyl ether provides the dihydroxy compound (XLIV), which is selectively monoprotected with Tips-OTf and 2,6-lutidine in dichloromethane to give the intermediate (XLV).