X-Ray Structure Analyses of syn/anti-Conformers of N-Furfuroyl-, N-Benzoyl-, and N-Picolinoyl-Substituted (2R)-Bornane-10,2-sultam Derivatives

✍ Scribed by Karolina Koszewska; Anna Piątek; Christian Chapuis; Janusz Jurczak

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: German
• Weight: 445 KB
• Volume: 91
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.200890153

✦ Synopsis

Abstract

The synthesis and the X‐ray structure of the three new N‐(arylcarbonyl)‐substituted derivatives 2a–2c of (2__R__)‐bornane‐10,2‐sultam are presented and discussed. Direct comparison of the solid‐state analyses shows that the dipole‐directed SO~2~/CO anti‐/__syn‐__conformations may be very sensitive to weak electronic/electrostatic repulsions of the heteroatom lone pairs. The optimum interactions are reached when the lone pair of the β‐positioned heteroatom is oriented in the O(3)C(11)N(1) plane. Such rare syn‐conformations may be observed with at least up to 1.8 kcal/mol higher energy as compared to their ground states. Additionally, these anti/__syn‐__conformations are also very sensitive to external influences such as, for example, the crystal‐packing forces.