合成路线1

A new strategy for the synthesis of a key intermediate in the preparation of LY-333531 has been described: Condensation of indole (I) with the tosylate (II) by means of NaH in DMF gives 4-(1-indolyl)butane-1,2-diol (III), which is monotritylated with trityl bromide yielding ether (IV). Alkylation of compound (IV) with tert-butyl bromoacetate (V) and NaH in THF affords the hydroxyacetic derivative (VI), which is reduced with LiBH4 in THF/EtOH to provide the carbinol (VII). Reaction of compound (VII) with Ms2O and pyridine in THF gives the mesylate (VIII), which is condensed with oxalyl chloride (IX) in ethyl ether to yield the oxoacetyl chloride (X). The alcoholysis of (X) with NaOMe in methanol affords the oxoacetate (XI), which is finally cyclized with 2-(3-indolyl)acetamide (XII) by means of NaH in DMF to provide the target intermediate (XIII).