Synthetische Verwendung von Epoxynitronen. III. Der anomere Effekt als bestimmender Faktor für die Konformation der 3‐Cyano‐perhydro‐1,2‐benzoxazine

Abstract

The anomeric effect as a conformation determining factor for 3‐cyano‐perhydro‐1,2‐benzoxazines An unusual population of conformer II is found by 1 H‐NMR. spectroscopy in the conformation equilibrium I⇄ II of 1b (Fig. 3) in which the non‐bonding nitrogen electronpair is anti‐periplanar to the CCN bond. This finding is interpreted in terms of a generalized anomeric effect operating in the α‐cyano‐hydroxylamin‐ether structural unit.