合成路线1

The intermediate (XLIII) has been obtained in two related ways: 1) The protection of (2S,3S,4S)-2,4-dimethyl-1-(tert-butyldimethylsilyloxy)-5-hexen-3-ol (I) with p-methoxybenzyl bromide and NaH gives the benzyl ether (XXXIV) which is ozonolyzed with O3, yielding the aldehyde (XXXV), which is condensed with the phosphonium salt (XXXVI) by means of KHMDS to afford the iodovinyl derivative (XXXVII). The homologation of (XXXVII) with vinylzinc bromide (XXXVIII) provides the octadiene derivative (XXXIX), which is desilylated with TFA, furnishing the primary alcohol (XL). The oxidation of (XL) with DMP gives the aldehyde (XLI), which is treated with CH3-MgBr, yielding the secondary alcohol (XLII). Finally, this alcohol is oxidized with DMP to the target intermediate ketone (XLIII). 2) The protection of (2S,3R,4S)-2,4-dimethyl-1-(tert-butyldimethylsilyloxy)-5-hexen-3-ol (XVII) with p-methoxybenzyl bromide and NaH gives the benzyl ether (XLIV), which is ozonolyzed with O3, yielding the aldehyde (XLV). The reaction of (XLV) with CH3-MgBr affords the secondary alcohol (XLVI), which is desilylated with TFA.