P. Dragovich, D. Murphy, Kimkim Dao
Dec 12, 2008
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Influential Citations
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Journal
Tetrahedron-asymmetry
Abstract
Abstract A 4-step synthesis of an optically active synthetic intermediate [(1 R ,2 S )-2-(4′-fluorobenzylamino)cyclopentanecarboxylic acid ethyl ester complex with ( S )-(+)-mandelic acid; compound 12 , >99% de] required for the preparation of a promising HCV NS5B polymerase inhibitor is reported. This process utilizes mandelic acid as a resolving agent, which can be recovered in good yield by a simple extraction. An optimized version of the chemistry described avoids the use of chromatographic purifications making it suitable for large-scale applications. In addition, the straightforward conversion of compound 12 to enantiomerically pure (1 R ,2 S )-2-aminocyclopentanecarboxylic acid ethyl ester and the corresponding Boc and Cbz derivatives is reported. The preparation of the enantiomer of 12 (compound 15 ) in enantiomerically pure form and the conversion of this entity to (1 S ,2 R )-2-aminocyclopentanecarboxylic acid ethyl ester and the corresponding Boc and Cbz derivatives is also described.