合成路线1

The reaction of 7-oxotricyclo[4.2.0.0(2.4)]octane-3-endo-carboxaldehyde neopentylglycol acetal (LIII) with dimethylsulfonium methylide (G) gives the spiroepoxide (LIV), which by isomerization with LiI in THF yields the tricyclononanone (LV). The reduction of (LV) with NaBH4 in ethanol, followed by acetylation with acetic anhydride in pyridine affords the tricyclic acetate (LVI), which is treated with formic acid to eliminate the acetalic residue and form the free aldehyde (LVII). The Wittig reaction of (LVII) with triphenylhexylidenephosphorane (LVIII) affords the tricyclic acetate (LIX), which is hydrolyzed with base and oxidized with Jones reagent to yield the tricyclic ketone (LX). The oxidation of the double bond of (LX) with 0sO4 gives the diol (LXI), which submitted successively to: triethyl orthopropionate (H) in pyridine, to anhydrous formic acid, to aqueous methanolic K2CO3 and to sodium metaperiodate, is converted into the previously obtained dihydroxyketone (XII). This compound can be used in the preceding syntheses or protected with dimethyltert-butylsilyl chloride to afford the bis(silyl) ether (LXII), which by reaction with the sulfoximine (LXIII), and then with AlHg is converted into the protected trialcohol (LXIV).