Unexpected Stereoselective 6-exo versus 7-endo Aryl Radical Cyclisation Controlled by Positional Isomers in a Chiral Octahydro-1,3-benzoxazine Moiety - Andrés, Celia; Duque-Soladana, Juan P; Iglesias, Jesús M; Pedrosa, Rafael (Synlett, 1997)