The first concise and collective
asymmetric total synthesis of
six 14-hydroxygelsenicine-related Gelsemium alkaloids,
i.e., 14-hydroxygelsedilam, 14-acetoxygelsedilam, gelsefuranidine,
gelsemolenine A, and gelselegandines B and C, was accomplished via
the facile construction of a 7-azabicyclo[4.2.1]nonane skeleton by
intramolecular aza-Michael addition, the preparation of an oxabicyclo[3.2.2]nonane
ring core with a secondary hydroxy group at C14 by an intramolecular
oxymercuration–hydroxylation strategy, and divergent transformations
of 14-hydroxygelsenicine into biogenetically related alkaloids.