| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 5277680 | Tetrahedron Letters | 2007 | 5 Pages |
We report the divergent effects of a 3a-methyl and 3a-phenyl substituent on the chemoselectivity and stereoselectivity of reduction of the enamide moiety of N-Boc-hexahydro-1H-indolin-5(6H)-ones. Under ionic reduction conditions (triethylsilane/trifluoroacetic acid) the enamide group of 3a-methyl-N-Boc-hexahydro-1H-indolin-5(6H)-one was reduced to afford exclusively a cis ring-fused product. For the 3a-phenyl substituted analogue more forcing conditions (sodium cyanoborohydride at pH 2–2.5) were required and resulted in the selective reduction of the enamide group to give a trans ring-fused product as well as reduction of the ketone group.
Graphical abstractWe report the divergent effects of a 3a-methyl and 3a-phenyl substituent on the chemoselectivity and stereoselectivity of reduction of the enamide moiety of N-Boc-tetrahydro-1H-indolin-5(6H)-ones.Figure optionsDownload full-size imageDownload as PowerPoint slide
