STEREOCHEMISTRY IN A MEDIUM-SIZED RING - HIGHLY DIASTEREOSELECTIVE N-OXIDATION OF A SUBSTITUTED 3-BENZAZONINE - X-RAY CRYSTAL-STRUCTURE OF AN UNUSUAL COMPLEX BETWEEN AN AMINE N-OXIDE AND SACCHARIN

Medium-sized cyclic compounds often adopt a wide range of low-energy conformations, which can render the control of reaction stereochemistry unpredictable or difficult.14 However, with the introduction of sp2 atoms into the ring, certain conformations may be significantly differentiated, so that impressive diastereoselection between remote sites (e.g., 1,3 and 1,4) can be achieved.13 Both Still1 and Vedejs2 have drawn attention to local conformational effects as a source of effective stereocontrol in such molecules. © 1990, American Chemical Society. All rights reserved.