A camphor-derived vinylsulfonium salt as a reagent for a cycloannulation

A chiral, non-racemic vinylsulfonium salt 6 was prepared from camphorquinone in seven steps and reacted with indole-2-carboxaldehyde to give a tricyclic azido alcohol 2 in a 35% yield and 43% e.e. and a 43% recovery of the chiral sulfide. (C) 2001 Elsevier Science Ltd. All rights reserved.