Importance of allylic interactions and stereoelectronic effects in dictating the steric course of the reaction of iminium ions with nucleophiles. An efficient total synthesis of (±) gephyrotoxin

Article abstract of DOI:10.1021/ja00354a031

A stereocontrolled total synthesis of (±)-gephyrotoxin in 15 steps and 6.5% overall yield from benzyl trans-1,3-butadiene-1-carbamate is described. A key step is reduction of octahydroquinoline 27 from the more hindered concave α face to provide decahydroquinoline 28. This unusual transformation results from the interplay of allylic (A¹,²) steric interactions and stereoelectronic effects.