合成路线1

The chiral 6(R) isomer of 213351 has been obtained as follows: The condensation of 1,1-diacetylcyclopropane monoethylene ketal (I) with acetylenic phosphonate (II) by means of NaHMDS in THF gives the silylated pentenyne (III), which is treated with TsOH in acetone/water yielding the acetylcyclopropane (IV). The Sharpless asymetric dihydroxylation of the double bond of (IV) by means of chiral auxiliary (DHQD)2PYR, K2OsO2(OH)4, K3Fe(CN)6 and K2CO3 in tert-butanol/water affords the chiral diol (V), which is monosilylated with TBDMS-OTf providing the silyl ether (VI). The condensation of (VI) with ethynylmagnesium bromide (VII) and CeCl3 gives the diacetylenic diol (VIII), which is regioselectively acetylated with Ac2O, TEA and DMAP yielding the monoacetate (IX). The treatment of the propargylic acetate (IX) with [(PPh3)CuH]6 in methanol affords the allene (X), which is regioselectively desilylated at the terminal acetylenic group furnishing the cyclization precursor (XI). The Mo(CO)6 promoted cyclization of (XI) in refluxing toluene/DMSO gives the chiral tricyclic ketone (XII). The methylation of (XII) with MeLi yields the monosilylated diol (XIII), which is desilylated with TBAF to the chiral diol (XIV). The oxidation of (XIV) with Dess Martin periodinane (DMP) affords the chiral hydroyketone (XV), which is finally hydroxymethylated with formaldehyde and H2SO4 to furnish the target compound.