合成路线1

In a different route, hydrogenation of (R)-3-chloro-1-phenyl-1-propanol (XV) over Rh/Al2O3 gave the cyclohexyl carbinol (XVI), which was protected as the ethoxyethyl ether (XVII) by treatment with ethyl vinyl ether in the presence of pyridinium tosylate. Lithiation of chloride (XVII), followed by exchange with lithium (2-thienyl)cyanocuprate, generated the organocuprate reagent (XVIII), which produced a conjugate addition to enone (XIX) to afford the methylene ketone (XX). Protecting group exchange in (XX) was effected by acidic cleavage of the ethoxyethyl group, followed by silylation with t-butyldimethylsilyl triflate, yielding the bis-silylated compound (XXI). The Z-vinylstannane reagent (XXII) was subjected to a stereospecific transmetalation with Me2Cu(CN)Li2 and the resulting cuprate underwent conjugate addition to enone (XXI) yielding adduct (XXIII). Reduction of ketone (XXIII) with L-Selectride®, followed by acidic cleavage of the ethoxyethyl group, provided diol (XXIV). Alkylation of (XXIV) with tert-butyl bromoacetate (X), followed by transterification as above, furnished the isopropyl ester (XXV). The remaining hydroxyl group of (XXV) was subsequently exchanged by a chloride (XXVI) via the corresponding mesylate. Finally, desilylation of (XXVI) with HF in THF gave rise to the title compound.