合成路线1

The condensation of 2'-bromo-4'-methylacetophenone (I) with benzaldehyde (II) by means of NaOMe in methanol gives the propenone (III), which is cyclized by means of PdCl2, PPh3 and K2CO3 in DMF, yielding 5-methyl-3-phenyl-1-indenone (IV). The enantioselective reduction of (IV) by means of borane/Me2S complex and (R)-3,3-diphenyl-1-methyltetrahydro-1H,3H-pyrrolo[1,2-c][1,3,2]oxazaborole [(R)-MeCBS] as chiral catalyst in THF affords 5-methyl-3(S)-phenylindan-1-ol (V), which is oxidized with 1,4-diazabicyclo[2,2,2]octane (DABCO) in refluxing THF/TEA to provide the corresponding indanone (VI). The oxidation of (VI) with MCPBA in dichloromethane gives 6-methyl-4(S)-phenyl-3,4-dihydro-2H-1-benzopyran-2-one (VII), which is reduced with DIBAL in toluene to yield 6-methyl-4(S)-phenyl-3,4-dihydro-2H-1-benzopyran-2-ol (VIII). Finally, this compound is reductocondensed with diisopropylamine (IX) by means of H2 over Pd/C in methanol to afford the target compound.