✦ LIBER ✦
ChemInform Abstract: Unexpected Stereoselective 6-exo versus 7-endo Aryl Radical Cyclization Controlled by Positional Isomers in a Chiral Octahydro-1,3-benzoxazine Moiety.
✍ Scribed by C. ANDRES; J. P. DUQUE-SOLADANA; J. M. IGLESIAS; R. PEDROSA
- Publisher
- John Wiley and Sons
- Year
- 2010
- Weight
- 33 KB
- Volume
- 29
- Category
- Article
- ISSN
- 0931-7597
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✦ Synopsis
Unexpected Stereoselective 6-exo versus 7-endo Aryl Radical Cyclization Controlled by Positional Isomers in a Chiral Octahydro-1,3-benzoxazine Moiety.
-Radical cyclization of benzoxazine (I) results in formation of two major cyclization diastereomers (II) and (III) via a 6-exo-trig process. Surprisingly, the positional isomeric precursor (V) undergoes exclusive 7-endo radical cyclization to the seven-membered ring system (VI). -