D. Crich, M. Bruncko, S. Natarajan
Feb 20, 1995
Citations
0
Influential Citations
14
Citations
Journal
Tetrahedron
Abstract
Abstract An indepth comparison of the solution (CDCl3, 1H-NMR) and solid state (X-ray) conformations of the hexahydropyrrolo[2,3-b]indoles 4, 5, and 6 is made. Close parallels with the literature conformations of the aflatoxin furo[2,3-b]benzofuran skeleton and with the conformation of the naturally occuring hexahydropyrrolindole physostigmine are noted. In the solid state the sulfonamide N in 4 – 6 is non-planar with various degrees of rotation about the SN bond. In solution, variable temperature 1H-NMR evidence indicates hindered rotation about the NS bond of the sulfonamide group in 4 – 6, possibly coupled to inversion of the pyramidal sulfonamide N atom. Reaction of 5 with LDA followed by quenching with methyl iodide resulted in alkylation with clean inversion of configuration.