合成路线1

Chiral acetylenic ketone intermediate (XXIV): The oxidation of 6-(trimethylsilyl)-5-hexyn-1-ol (XVI) with PCC in DMF gives the carboxylic acid (XVII), which is condensed with the chiral auxiliary (XVIII) by means of Piv-Cl and TEA in THF to yield the acyloxazolidine (XIX). The diastereoselective methylation of (XIX) with Me-I and NaHMDS in THF affords the methylated compound (XX), which by reductive elimination of the chiral auxiliary with LiBH4 in ethyl ether provides the chiral alcohol (XXI). The oxidation of (XXI) with (COCl)2 and DMSO in dichloromethane leads to the aldehyde (XXII), which by a Grignard reaction with Me-MgBr in ethyl ether is converted into the secondary alcohol (XXIII). Finally, this compound is oxidized with (COCl)2 as before to yield the chiral acetylenic ketone intermediate (XXIV)