反应详情

Trans-1,2,3,5,6,10b-hexahydro-6-(4'-iodophenyl)pyrrolo[2,1-a]isoquinoline (trans-6), was synthesized by a four step reaction sequence outlined in FIG. 1A. 4-Bromomandelic acid (1) was coupled with 2-phenylpyrrolidine (2) in the presence of BOP reagent to yield 2-phenylpyrrolidino 4-bromophenyl-α-hydroxyacetate (3). Upon treatment with PPA, the amide 3 was cyclized to the lactam (4) which was reduced with aluminum hydride to provide a pair of diastereomers (5) with a trans-to-cis ratio of 2. The desired trans-6-(4'-bromophenol)-1,2,3,5,6,10b-hexahydropyrrolo[2,1-a]-isoquinoline (trans 5) was separated by flash chromatography. Trans-5 was treated with butyllithium followed by iodination to afford trans-1,2,3,5,6,10b-hexahydro-6-(4'-iodophenyl) pyrrolo [2,1-a]isoquinoline (trans-6). Enantiomeric enriched (+)-(6S, 10bR)-1,2,3,5,6,10b-hexahydro-6-(4'-iodophenyl)pyrrolo[2,1-a]isoquinoline was obtained by the same reaction sequence starting with (+)-2(R)-phenylpyrrolidine.