The asymmetric ene reaction of N-glyoxyloyl-(2R)-bornane-10,2-sultam with 1-pentene and 1-hexene

Article abstract of DOI:10.1016/S0957-4166(97)00130-4

The asymmetric ene reaction of N-glyoxyloyl-(2R)-bornane-10,2-sultam 2 and its hemiacetal 3 with 1-pentene 4 and 1-hexene 5 in the presence of Lewis acids is reported. All the ene reactions studied led to diastereoisomeric mixtures of olefins 6 and 7 or 8 and 9, with predominance of products of the (S) absolute configuration on the newly formed stereogenic center. The absolute configuration (via X-ray analysis of 6 and chemical correlation) and the extent of asymmetric induction were established. Stereochemical models are proposed.